@article{EnglischBarberkaPietschetal.1995,
  author    = {Englisch, Uwe and Barberka, Thomas Andreas and Pietsch, Ullrich and H{\"o}hne, U.},
  title     = {Investigation of the chain-chain interface in a lead-stearate multilayer using neutron reflectivity},
  year      = {1995},
  language  = {en}
}
@article{ReichePenacoradaGeueetal.1995,
  author    = {Reiche, J{\"u}rgen and Penacorada, Florencio and Geue, Thomas and Pietsch, Ullrich and Brehmer, Ludwig},
  title     = {In-plane structure of uranylarachidate multilayers},
  year      = {1995},
  language  = {en}
}
@article{StahnMoehlePietsch1996,
  author    = {Stahn, Jochen and M{\"o}hle, Marcus and Pietsch, Ullrich},
  title     = {Accurate structure determination for GaAs using Pendell{\"o}sung oscillation},
  year      = {1996},
  language  = {en}
}
@article{PietschHansen1996,
  author    = {Pietsch, Ullrich and Hansen, N. K.},
  title     = {A critical review of the valence charge density in GaAs},
  year      = {1996},
  language  = {en}
}
@article{LichanotAzavantPietsch1996,
  author    = {Lichanot, Albert and Azavant, P. and Pietsch, Ullrich},
  title     = {Ab-initio Hartree-Fock study of the electronic charge density of the cubic boron nitride and its comparison with the experiment},
  year      = {1996},
  language  = {en}
}
@article{ReicheKnochenhauerDieteletal.1997,
  author    = {Reiche, J{\"u}rgen and Knochenhauer, Gerald and Dietel, Reinhard and Freydank, Anke-Christine and Zetzsche, Thomas and Pietsch, Ullrich and Brehmer, Ludwig and Barberka, Thomas Andreas and Geue, Thomas},
  title     = {Structure of thermally treated oxadiazoleamide Langmuir-Blodgett films},
  year      = {1997},
  abstract  = {The thermal treatment of Y-type Langmuir-Blodgett (LB) films formed from the amphiphilic derivative of 2,5- diphenyl-1,3,4-oxadiazole 1 results in changes of the molecular packing. These changes have been analysed by a combination of X-ray specular reflectivity data, X-ray grazing incidence diffraction data and scanning force microscopy images, On the basis of these experimental data we have simulated possible supramolecular structures, These simulations provide insight into the intermolecular interactions giving rise to the observed structural transitions. The crystalline structure induced by thermal treatment of the LB films is characterized by a uniaxial texture, which is correlated with the dipping direction during deposition of the LB film.},
  language  = {en}
}
@article{ReichePenacoradaGeueetal.1997,
  author    = {Reiche, J{\"u}rgen and Penacorada, Florencio and Geue, Thomas and Pietsch, Ullrich and Brehmer, Ludwig},
  title     = {Monolayers and multilayers of uranyl arachidate : in-plane structure of uranyl arachidate multilayers},
  year      = {1997},
  abstract  = {The molecular in-plane structure of uranyl arachidate Langmuir-Blodgett (LB) films formed at different subphase pH values was analysed by means of X-ray grazing-incidence diffraction. For multilayers formed at low subphase pH a reorganisation of the arachidic acid film structure is confirmed. At appropriate subphase pH values, reorganisation of the film structure, e.g. via the formation of three-dimensional crystallites, is prevented by the presence of the uranyl ions and by the subsequent introduction of conformational disorder (gauche defects) in the alkyl chains. The observation of a macroscopic flow-induced in-plane texture in these uranyl arachidate LB films has profound implications for the design of ordered, supramolecular structures by the Langmuir-Blodgett technique.},
  language  = {en}
}
@article{PietschBarberkaGeueetal.1997,
  author    = {Pietsch, Ullrich and Barberka, Thomas Andreas and Geue, Thomas and St{\"o}mmer, Ralph},
  title     = {X-ray scattering from thin organic films and multilayers},
  year      = {1997},
  language  = {en}
}
@article{EnglischGutberletSeitzetal.1997,
  author    = {Englisch, Uwe and Gutberlet, T. and Seitz, R. and Oeser, R. and Pietsch, Ullrich},
  title     = {Thermally induced rearrangement of fatty acid salt molecules in Langmuir-Blodgett multilayers},
  year      = {1997},
  language  = {en}
}
@article{DarowskiPaschkePietschetal.1997,
  author    = {Darowski, Nora and Paschke, K. and Pietsch, Ullrich and Wang, K. H. and Forchel, Alfred and Baumbach, Tilo and Zeimer, Ute},
  title     = {Identification of a buried single quantum well within surface structurized semiconductors using depth resolved x-ray grazing-incidence diffraction},
  year      = {1997},
  language  = {en}
}
@article{RosePietschZeimer1997,
  author    = {Rose, Dirk and Pietsch, Ullrich and Zeimer, Ute},
  title     = {Characterization of InGaAs single quantum wells buried in GaAs[001] by grazing incidence diffraction},
  year      = {1997},
  language  = {en}
}
@article{BolmEnglischPenacoradaetal.1997,
  author    = {Bolm, A. and Englisch, Uwe and Penacorada, Florencio and Gerstenberger, M. and Pietsch, Ullrich},
  title     = {Temperature and time dependent investigations of cd- and uranyl-stearate multilayers by means of neutron reflectivity measurements},
  year      = {1997},
  language  = {en}
}
@article{HerrmannKauppGeueetal.1997,
  author    = {Herrmann, A. and Kaupp, G. and Geue, Thomas and Pietsch, Ullrich},
  title     = {AFM and GID investigations of the gas-solid diazotation of 4-sulfanil-acid-monohydrat single crystals},
  year      = {1997},
  language  = {en}
}
@article{PaschkeGeueBarberkaetal.1997,
  author    = {Paschke, K. and Geue, Thomas and Barberka, Thomas Andreas and Bolm, A. and Pietsch, Ullrich and R{\"o}sch, M. and Batke, Edwin and Faller, F. and Kerkel, K. and Oshiniwo, J. and Forchel, Alfred},
  title     = {Characterization of lateral semiconductor nano structures by means of x-ray grazing-incidence diffraction},
  year      = {1997},
  language  = {en}
}
@article{SiebrechtSchreyerEnglischetal.1997,
  author    = {Siebrecht, R. and Schreyer, A. and Englisch, Uwe and Pietsch, Ullrich and Zabel, Hartmut},
  title     = {The new reflectometer ADAM at the ILL},
  year      = {1997},
  language  = {en}
}
@article{NeissendorferBolmPietsch1997,
  author    = {Neißendorfer, Frank and Bolm, A. and Pietsch, Ullrich},
  title     = {Energy dispersive X-ray reflectometry and X-ray grazing incidence diffraction from organic multilayers},
  year      = {1997},
  language  = {en}
}
@article{DarowskiPietschWangetal.1998,
  author    = {Darowski, Nora and Pietsch, Ullrich and Wang, K. H. and Forchel, Alfred and Shen, W. and Kycia, S.},
  title     = {X-ray diffraction analysis of strain relaxation in free standing and buried GaAs/GaInAs/GaAs SQW lateral structures},
  year      = {1998},
  language  = {en}
}
@article{HaierHerrmannEsseretal.1998,
  author    = {Haier, P. and Herrmann, B. A. and Esser, N. and Pietsch, Ullrich and L{\"u}ders, K. and Richter, W.},
  title     = {Influence of the deposition rate on the structure of thin metal layers},
  year      = {1998},
  language  = {en}
}
@article{StahnPucherGeueetal.1998,
  author    = {Stahn, Jochen and Pucher, Andreas and Geue, Thomas and Daniel, A. and Pietsch, Ullrich},
  title     = {Electric field induced electron density response of GaAs and ZnSe},
  year      = {1998},
  language  = {en}
}
@article{DarowskiLuebbertPietschetal.1998,
  author    = {Darowski, Nora and L{\"u}bbert, Daniel and Pietsch, Ullrich and Zhuang, Y. and Zerlauth, S. and Bauer, G{\"u}nther},
  title     = {In-plane strain and strain relaxation in laterally patterned Si/SiGe quantum dots and wire arrays},
  year      = {1998},
  language  = {en}
}
@article{StoemmerGoebelHubetal.1998,
  author    = {St{\"o}mmer, Ralph and G{\"o}bel, H. and Hub, W. and Pietsch, Ullrich},
  title     = {X-ray scattering from silicon surfaces},
  year      = {1998},
  language  = {en}
}
@article{StoemmerMartinGeueetal.1998,
  author    = {St{\"o}mmer, Ralph and Martin, C. R. and Geue, Thomas and G{\"o}bel, H. and Hub, W. and Pietsch, Ullrich},
  title     = {Comparative studies of fractal parameters of Si(100) surfaces measured by X-ray scattering and atomic force microscopy},
  year      = {1998},
  language  = {en}
}
@article{DarowskiPietschZeimeretal.1998,
  author    = {Darowski, Nora and Pietsch, Ullrich and Zeimer, Ute and Smirnitzki, V. and Bugge, F.},
  title     = {Nondestructive analysis of a lateral GaAs nanostructure buried under AlGaAs using conventional high resolution and grazing incidence X-ray diffraction},
  year      = {1998},
  language  = {en}
}
@article{DarowskiPaschkePietschetal.1998,
  author    = {Darowski, Nora and Paschke, K. and Pietsch, Ullrich and Wang, K. H. and Forchel, Alfred and L{\"u}bbert, Daniel and Baumbach, Tilo},
  title     = {Structural characterization of a GaAs surface wire structure by triple-axis X-ray grazing incidence diffraction},
  year      = {1998},
  language  = {en}
}
@article{UlyanenkovKlemradtPietsch1998,
  author    = {Ulyanenkov, A. and Klemradt, U. and Pietsch, Ullrich},
  title     = {Investigation of strain relaxation in GaInAs/GaAs superlattices by x-ray diffuse scattering},
  year      = {1998},
  language  = {en}
}
@article{GrenzerSchomburgLingottetal.1998,
  author    = {Grenzer, J{\"o}rg and Schomburg, E. and Lingott, I. and Ignotov, A. a. and Renk, K. F. and Pietsch, Ullrich and Rose, Dirk and Zeimer, Ute and Melzer, B. J. and Ivanov, S. and Schaposchnikov, S. and Kop'ev, P. S. and Pavel'ev, D. G. and Koschurinov, Yu.},
  title     = {X-ray and transport characterization of an Esaki-Tsu superlattice device},
  year      = {1998},
  language  = {en}
}
@article{StahnMoehlePietsch1998,
  author    = {Stahn, Jochen and M{\"o}hle, Marcus and Pietsch, Ullrich},
  title     = {Comparison of theoretical and experimental structure amplitudes of GaAs},
  year      = {1998},
  language  = {en}
}
@article{TsirelsonAbramovZavodniketal.1998,
  author    = {Tsirelson, Vladimir G. and Abramov, Yury Fedorovich and Zavodnik, Valerie E. and Stash, Adam I. and Belokoneva, Elena L. and Stahn, Jochen and Pietsch, Ullrich and Feil, Dirk},
  title     = {Critical pionts in a crystal an procrystal},
  year      = {1998},
  language  = {en}
}
@article{EnglischPenacoradaSamoilenkoetal.1998,
  author    = {Englisch, Uwe and Penacorada, Florencio and Samoilenko, I. and Pietsch, Ullrich},
  title     = {Investigation of the vertical molecular exchange in a complex organic multilayer system},
  year      = {1998},
  language  = {en}
}
@article{ZhuangHolyStangletal.1999,
  author    = {Zhuang, Y. and Hol{\´y}, V{\´a}clav and Stangl, Jochen and Darhuber, A. and Mikulik, P. and Zerlauth, S. and Sch{\"a}ffler, F. and Bauer, G{\"u}nther and Darowski, Nora and L{\"u}bbert, Daniel and Pietsch, Ullrich},
  title     = {Strain relaxation in periodic arrays of Si/SiGe quantum wires determined by coplanar high-resolution x-ray diffrcation and grazing-incidence diffraction},
  year      = {1999},
  language  = {en}
}
@article{ZeimerBaumbachGrenzeretal.1999,
  author    = {Zeimer, Ute and Baumbach, Tilo and Grenzer, J{\"o}rg and L{\"u}bbert, Daniel and Mazuelas, A. and Pietsch, Ullrich and Erbert, G.},
  title     = {In-situ characterization of strain distribution in broad-area high-power lasers under operation by high- resolution x-ray diffrcation and topography using synchrotron radiation},
  year      = {1999},
  language  = {en}
}
@article{EnglischKatholyPenacoradaetal.1999,
  author    = {Englisch, Uwe and Katholy, Stefan and Penacorada, Florencio and Reiche, J{\"u}rgen and Pietsch, Ullrich},
  title     = {Investigation of molecular diffusion across organic multilayers using neutron specular reflectivity},
  year      = {1999},
  language  = {en}
}
@article{UlyanenkovDarowskiGrenzeretal.1999,
  author    = {Ulyanenkov, A. and Darowski, Nora and Grenzer, J{\"o}rg and Pietsch, Ullrich and Wang, K. H. and Forchel, Alfred},
  title     = {Evaluation of strain distribution in freestanding and bruied lateral nanostructures},
  year      = {1999},
  language  = {en}
}
@article{StahnPucherPietschetal.1999,
  author    = {Stahn, Jochen and Pucher, Andreas and Pietsch, Ullrich and Zellner, J. and Weckert, E.},
  title     = {Experimental determination of electric field induced differences in structure factor phases in the order of 2\%},
  year      = {1999},
  language  = {en}
}
@article{VeldkampErkoGudatetal.1999,
  author    = {Veldkamp, Markus and Erko, Alexei and Gudat, Wolfgang and Abrosimov, Nikolai V. and Alex, Volker and Khasanov, Salavat and Neissendorfer, Frank and Pietsch, Ullrich and Shekhtman, Veniamin},
  title     = {Si(1-x)Ge(x) laterally graded crystals as monochromators for X-Ray absorption spectroscopy studies},
  year      = {1999},
  language  = {en}
}
@article{UlyanenkovBaumbachDarowskietal.1999,
  author    = {Ulyanenkov, A. and Baumbach, Tilo and Darowski, Nora and Pietsch, Ullrich and Wang, K. H. and Forchel, Alfred and Wiebach, T.},
  title     = {Investigation of the in-plane strain distribution in free-standing GaAs/InGaAs/GaAs single quantum well surface nanostructures on GaAs[001]},
  year      = {1999},
  language  = {en}
}
@article{HolyDarhuberStangletal.1999,
  author    = {Hol{\´y}, V{\´a}clav and Darhuber, A. and Stangl, Jochen and Zerlauth, S. and Sch{\"a}ffler, F. and Bauer, G{\"u}nther and Darowski, Nora and L{\"u}bbert, Daniel and Pietsch, Ullrich and Vavra, I.},
  title     = {HRXRD and GID investigations of a self-organized SiGe quantum dot multilayer},
  year      = {1999},
  language  = {en}
}
@article{NeissendorferPietschBreszisinskietal.1999,
  author    = {Neißendorfer, Frank and Pietsch, Ullrich and Breszisinski, G. and M{\"o}hwald, Helmuth},
  title     = {Energy-dispersive reflectometry and diffractometry at the WLS of BESSY-I},
  year      = {1999},
  language  = {en}
}
@article{LuebbertBaumbachPontietal.1999,
  author    = {L{\"u}bbert, Daniel and Baumbach, Tilo and Ponti, S. and Pietsch, Ullrich and Leprince, L. and Schneck, J. and Talneau, A.},
  title     = {Strain investigation of low strained buried gratings by grazing incidence X-Ray diffraction and the theory of elasticity},
  year      = {1999},
  language  = {en}
}
@article{GeueSchultzEnglischetal.1999,
  author    = {Geue, Thomas and Schultz, M. and Englisch, Uwe and St{\"o}mmer, Ralph and Pietsch, Ullrich and Meine, Kerstin and Vollhard, D.},
  title     = {Investigation of pH-dependent domain structure of fatty acid salt Langmuir-Blodgett films by means of X-ray diffuse scattering and Atomic Force Microscopy},
  year      = {1999},
  language  = {en}
}
@book{HolyPietschBaumbach1999,
  author    = {Hol{\´y}, V{\´a}clav and Pietsch, Ullrich and Baumbach, Tilo},
  title     = {High-resolution x-ray scattering from thin films and multilayers},
  series = {Springer tracts in modern physics},
  volume    = {149},
  journal   = {Springer tracts in modern physics},
  publisher = {Springer},
  address   = {Berlin, Heidelberg},
  isbn      = {3-540-62029-X},
  doi       = {10.1007/BFb0109385},
  pages     = {256 S.},
  year      = {1999},
  language  = {en}
}
@article{MetzgerPietschGarstein1999,
  author    = {Metzger, T. H. and Pietsch, Ullrich and Garstein, E.},
  title     = {High-resolution lattice parameter measurement by x-ray grazing incidence diffraction: Application to the interface of silicon on sapphire},
  year      = {1999},
  language  = {en}
}
@article{EnglischPenacoradaBrehmeretal.1999,
  author    = {Englisch, Uwe and Penacorada, Florencio and Brehmer, Ludwig and Pietsch, Ullrich},
  title     = {X-ray and neutron reflection analysis of the structure and the molecular exchange process in simple and complex fatty acid salt Langmuir-Blodgett multilayers},
  year      = {1999},
  language  = {en}
}
@article{HolyStanglZerlauthetal.1999,
  author    = {Hol{\´y}, V{\´a}clav and Stangl, Jochen and Zerlauth, S. and Bauer, G{\"u}nther and Darowski, Nora and L{\"u}bbert, Daniel and Pietsch, Ullrich},
  title     = {Lateral arrangement of self-assembled quantum dots in an SiGe/Si superlattice},
  year      = {1999},
  language  = {en}
}
@article{StruthDecherSchmittetal.1999,
  author    = {Struth, Bernd and Decher, Gero and Schmitt, J. and Hofmeister, Wolfgang and Neißendorfer, Frank and Pietsch, Ullrich and Brezesinski, Gerald and M{\"o}hwald, Helmuth},
  title     = {Chemical modification of Topaz surfaces},
  issn      = {0928-4931},
  year      = {1999},
  language  = {en}
}
@article{GeuePietschHaferkornetal.1999,
  author    = {Geue, Thomas and Pietsch, Ullrich and Haferkorn, J. and Stumpe, Joachim and Date, R. W. and Fawcett, A. H.},
  title     = {Competition of alignment and aggregation? : Phenomena in constrained films of LC poly(olefin ulfone)s and maleic anhydride co- and terpolymers},
  year      = {1999},
  language  = {en}
}
@article{ZeimerBuggeGramlichetal.2000,
  author    = {Zeimer, Ute and Bugge, F. and Gramlich, S. and Smirnitzki, V. and Weyers, Markus and Tr{\"a}nkle, G. and Grenzer, J{\"o}rg and Pietsch, Ullrich and Cassabois, G. and Emiliani, V. and Lienau, C.},
  title     = {Evidence for strain-induced lateral carrier confinement in InGaAs quantum wells by low-temperature near-field spectroscopy},
  year      = {2000},
  language  = {en}
}
@article{MukherjeeBhattacharyaSanyaletal.2000,
  author    = {Mukherjee, M. and Bhattacharya, M. K. and Sanyal, M. K. and Geue, Thomas and Grenzer, J{\"o}rg and Pietsch, Ullrich},
  title     = {Temperature dependent thickness and surface tension of polymer films},
  isbn      = {81-7371295-6},
  year      = {2000},
  language  = {en}
}
@article{Pietsch2000,
  author    = {Pietsch, Ullrich},
  title     = {Investigations of semiconductor surfaces and interfaces by X-ray grazing incidence diffraction},
  issn      = {0011-3891},
  year      = {2000},
  language  = {en}
}
@article{ZhuangPietschStangletal.2000,
  author    = {Zhuang, Y. and Pietsch, Ullrich and Stangl, Jochen and Hol{\´y}, Vaclav and Darowski, Nora and Grenzer, J{\"o}rg and Zerlauth, S. and Sch{\"a}ffler, F. and Bauer, G{\"u}nther},
  title     = {In-plane strain and shape analysis of Si/SiGe nanostructures by grazing incidence diffraction},
  year      = {2000},
  language  = {en}
}
@article{ZhuangSchellingStangletal.2000,
  author    = {Zhuang, Y. and Schelling, Christoph and Stangl, Jochen and Penn, C. and Senz, S. and Sch{\"a}ffler, Friedrich and Roche, T. and Daniel, A. and Grenzer, J{\"o}rg and Pietsch, Ullrich and Bauer, G{\"u}nther},
  title     = {Structural and optical properties of Si/Si{1-x}Ge{x} wires},
  year      = {2000},
  language  = {en}
}
@article{GrenzerDarowskiPietschetal.2000,
  author    = {Grenzer, J{\"o}rg and Darowski, Nora and Pietsch, Ullrich and Daniel, A. and Reithmaier, Johann-Peter and Rennon, Siegfried and Forchel, Alfred},
  title     = {Grazing-incidence diffraction strain analysis of a laterally-modulated multiquantum well system produced by focused-ion-beam implantation},
  year      = {2000},
  language  = {en}
}
@article{KarcenkoEnglischGrenzeretal.2000,
  author    = {Karcenko, Anatolij V. and Englisch, Uwe and Grenzer, J{\"o}rg and Geue, Thomas and Pietsch, Ullrich and Siebrecht, R.},
  title     = {Investigation of partially deuterated multilayers by means of X-ray and polarized neutron reflectometry},
  issn      = {1044-8632},
  year      = {2000},
  language  = {en}
}
@article{ThuenemannKubowiczPietsch2000,
  author    = {Th{\"u}nemann, Andreas F. and Kubowicz, Stephan and Pietsch, Ullrich},
  title     = {Ultra-thin solid polyelectrolyte-surfactant complex films : structure and wetting},
  year      = {2000},
  language  = {en}
}
@article{PietschRochonNatansohn2000,
  author    = {Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria},
  title     = {Formation of a buried lateral density grating in azopenzene polymer films},
  year      = {2000},
  language  = {en}
}
@article{PietschDarowskiUlyanenkovetal.2000,
  author    = {Pietsch, Ullrich and Darowski, Nora and Ulyanenkov, A. and Grenzer, J{\"o}rg and Wang, K. H. and Forchel, Alfred},
  title     = {Analysis of the strain distribution in lateral nanostructures for interpreting photoluminescence data},
  year      = {2000},
  language  = {en}
}
@article{StahnGeueGrenzeretal.2000,
  author    = {Stahn, Jochen and Geue, Thomas and Grenzer, J{\"o}rg and Pietsch, Ullrich},
  title     = {Interaction of short-chain alkanes with surface and interfaces of multilayer films built from amphiphilic molecules: an in-situ X-ray and neutron scattering probe},
  year      = {2000},
  language  = {en}
}
@article{NeumannBuchsteinerMahleretal.2000,
  author    = {Neumann, Werner and Buchsteiner, Alexandra and Mahler, Willy and Geue, Thomas and Pietsch, Ullrich},
  title     = {Dielectric loss spectroscopy at fatty acid salt multilayers},
  year      = {2000},
  abstract  = {Dielectric loss spectroscopy (DLS) was performed at compact samples and lamellary organized Langmuir-Blodgett (LB) films from various fatty acid salts. Previous thermoanalytical measurements at compact samples revealed the appearance of two different phase transition temperatures; the lower one is related to the acid the second one to the acid salt molecules. In spite of ill defined electrical contacts with the film the characteristic DLS frequencies obtained from about 100nm thick multilayer films are similar to those recorded from bulk samples. No significant variations of frequencies were found changing the counter ions. Besides conductivity influence at low frequncies we found two relaxations related to the mobility of the dipolar carboxylat-metal group at about 100 and 10000Hz. One of these frequencies is related to the rotation around the chain axis. The strength of this relaxation increases significantly with increasing the sample temperature above 105°C. This temperature is connected with a structural phase transition observed by X-ray reflectometry. In case of Pb-stearate the results of the dielectric measurements help to interprete this structural change as a transition from an orthorhombic into a free-rotator phase. The uncorrelated rotation of molecules around their molecular axes initiates a much increased relaxation strength at the carboxylat-metal sites.},
  language  = {en}
}
@article{MukhopadhyayDattaSanyaletal.2001,
  author    = {Mukhopadhyay, M. K. and Datta, A. and Sanyal, M. K. and Geue, Thomas and Pietsch, Ullrich},
  title     = {Synchrotron Studies of Melting of Langmuir-Blodgett Films},
  year      = {2001},
  language  = {en}
}
@article{AvilovLepeshovPietschetal.2001,
  author    = {Avilov, Anatoly S. and Lepeshov, G. G. and Pietsch, Ullrich and Tsirelson, Vladimir G.},
  title     = {Multipole analysis of the electron density and electrostatic potential in Germanium by high-resolution electron diffraction},
  issn      = {0022-3697},
  year      = {2001},
  language  = {en}
}
@article{DavaasambuuDanielStahnetal.2001,
  author    = {Davaasambuu, Jav and Daniel, A. and Stahn, Jochen and Pietsch, Ullrich},
  title     = {Comparison of experimental and theoretical valence charge densites in cubic ZnSe},
  issn      = {0022-3697},
  year      = {2001},
  language  = {en}
}
@article{GrenzerDarowskiGeueetal.2001,
  author    = {Grenzer, J{\"o}rg and Darowski, Nora and Geue, Thomas and Pietsch, Ullrich and Daniel, A. and Rennon, Siegfried and Reithmaier, Johann-Peter and Forchel, Alfred},
  title     = {Strain analysis and quantum well intermixing of a laterally modulated multiquantum well system produced by focused ion beam implantation},
  year      = {2001},
  language  = {en}
}
@article{ZeimerGrenzerPietschetal.2001,
  author    = {Zeimer, Ute and Grenzer, J{\"o}rg and Pietsch, Ullrich and Bugge, F. and Smirnitzki, V. and Weyers, Markus},
  title     = {Investigation of strain-modulated InGaAs-nanostructures by grazing-incidence x-ray diffraction and photoluminescence},
  year      = {2001},
  language  = {en}
}
@article{ZeimerBuggeGramlichetal.2001,
  author    = {Zeimer, Ute and Bugge, F. and Gramlich, S. and Smirnitzki, V. and Weyers, Markus and Tr{\"a}nkle, G. and Grenzer, J{\"o}rg and Pietsch, Ullrich and Cassabois, G. and Emiliani, V. and Linau, Christoph},
  title     = {Evidence of strain-induced lateral carrier confinement in InGaAs-quantum wells by low-temperature near-field spectroscopy},
  year      = {2001},
  language  = {en}
}
@article{PietschGrenzerGeueetal.2001,
  author    = {Pietsch, Ullrich and Grenzer, J{\"o}rg and Geue, Thomas and Neißendorfer, Frank and Brezesinski, Gerald and Symietz, Christian and M{\"o}hwald, Helmuth and Gudat, Wolfgang},
  title     = {The energy dispersive reflectometer at BESSY II : a challenge for thin film analysis},
  issn      = {0167- 5087},
  year      = {2001},
  language  = {en}
}
@article{PietschZeimerHofmannetal.2001,
  author    = {Pietsch, Ullrich and Zeimer, Ute and Hofmann, L. and Grenzer, J{\"o}rg and Gramlich, S.},
  title     = {Strain induced compositional modulations in AlGaAs overlayers induced by lateral surface gratings},
  issn      = {0272-9172},
  year      = {2001},
  language  = {en}
}
@article{DavaasambuuDanielStahnetal.2001,
  author    = {Davaasambuu, Jav and Daniel, A. and Stahn, Jochen and Pietsch, Ullrich},
  title     = {Harmonic and anharmonic thermal vibrations in cubic ZnSe},
  issn      = {0044-2968},
  year      = {2001},
  language  = {en}
}
@article{TsirelsonAvilovLepeshovetal.2001,
  author    = {Tsirelson, Vladimir G. and Avilov, Anatoly S. and Lepeshov, G. G. and Kuligin, A. K. and Stahn, Jochen and Pietsch, Ullrich and Spence, J. C. H.},
  title     = {Quantitative Analysis of the Inner-Crystal Electrostatic Potential of several Rock-Salt-Structure Crystals Using Accurate Electron-Diffraction Data},
  issn      = {1089-5647},
  year      = {2001},
  language  = {en}
}
@article{StahnPietschBlahaetal.2001,
  author    = {Stahn, Jochen and Pietsch, Ullrich and Blaha, Pawel and Schwarz, K. H.},
  title     = {Electric field induced charge-density variations in covalently bonded compounds},
  year      = {2001},
  language  = {en}
}
@article{PoloucekPietschGeueetal.2001,
  author    = {Poloucek, P. and Pietsch, Ullrich and Geue, Thomas and Symietz, Christian and Brezesinski, Gerald},
  title     = {X-ray reflectivity analysis of thin complex Langmuir-Blodgett films},
  year      = {2001},
  language  = {en}
}
@article{PietschStahnDavaasambuuetal.2001,
  author    = {Pietsch, Ullrich and Stahn, Jochen and Davaasambuu, Jav and Pucher, Andreas},
  title     = {Electric field induced charge density variations in partially-ionic compounds},
  issn      = {0022-3697},
  year      = {2001},
  language  = {en}
}
@article{HennebergChiGeueetal.2001,
  author    = {Henneberg, Oliver and Chi, Li Feng and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria},
  title     = {Atomic force microscopy inspection of the early state of formation of polymer surface relief grating},
  year      = {2001},
  language  = {en}
}
@article{HennebergGeueSaphiannikovaetal.2001,
  author    = {Henneberg, Oliver and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria},
  title     = {Formation and dynamics of polymer surface relief gratings},
  issn      = {0378-5963},
  year      = {2001},
  language  = {en}
}
@article{Pietsch2002,
  author    = {Pietsch, Ullrich},
  title     = {Reversible negative thermal expansion of polymer films},
  year      = {2002},
  language  = {en}
}
@article{Pietsch2002,
  author    = {Pietsch, Ullrich},
  title     = {X-ray reflectivity from sinusoidal surface relief gratings},
  year      = {2002},
  language  = {en}
}
@article{BodenthinGrenzerLauteretal.2002,
  author    = {Bodenthin, Yves and Grenzer, J{\"o}rg and Lauter, Robert and Pietsch, Ullrich and Lehmann, Pit and Kurth, Dirk G. and M{\"o}hwald, Helmuth},
  title     = {Temperature and time resolved x-ray scattering at thin organic films},
  year      = {2002},
  language  = {en}
}
@article{GeueHennebergPietsch2002,
  author    = {Geue, Thomas and Henneberg, Oliver and Pietsch, Ullrich},
  title     = {X-ray reflectivity from sinusoidal surface relief gratings},
  issn      = {0023-4753},
  year      = {2002},
  language  = {en}
}
@article{GeueSaphiannikovaHennebergetal.2002,
  author    = {Geue, Thomas and Saphiannikova, Marina and Henneberg, Oliver and Pietsch, Ullrich and Rochon, Paul and Natansohn, Almeria},
  title     = {Formation mechanism and dynamics in polymer surface gratings},
  year      = {2002},
  language  = {en}
}
@article{GeueHennebergGrenzeretal.2002,
  author    = {Geue, Thomas and Henneberg, Oliver and Grenzer, J{\"o}rg and Pietsch, Ullrich and Natansohn, Almeria and Rochon, Paul and Finkelstein, Kenneth D.},
  title     = {Formation of a buried density grating on thermal erasure of azobenzene polymer surface gratings},
  issn      = {0927-7757},
  year      = {2002},
  language  = {en}
}
@article{PietschKubowiczThuenemannetal.2003,
  author    = {Pietsch, Ullrich and Kubowicz, Stephan and Th{\"u}nemann, Andreas F. and Geue, Thomas and Watson, M. D. and Tchebotareva, N. and M{\"u}llen, K.},
  title     = {X-ray reflectivity study of an amphiphilic hex-peri-hexabenzocoronene at a structured silicon wafer surface},
  year      = {2003},
  language  = {en}
}
@article{PietschHesseZhuangetal.2003,
  author    = {Pietsch, Ullrich and Hesse, A. and Zhuang, Y. and Hol{\´y}, Vaclav and Stangl, Jochen and Zerlauth, S. and Schaffler, F. and Bauer, G{\"u}nther},
  title     = {X-ray grazing-incidence study of inhomogeneous strain relaxation in Si/SiGe wires},
  issn      = {0168-583X},
  year      = {2003},
  language  = {en}
}
@article{PietschZeimerGrenzeretal.2003,
  author    = {Pietsch, Ullrich and Zeimer, Ute and Grenzer, J{\"o}rg and Grigorian, Souren A. and Fricke, J. and Gramlich, S. and Bugge, F. and Weyers, Markus and Trankle, G.},
  title     = {Influence of lateral patterning geometry on lateral carrier confinement in strain-modulated InGaAs- nanostructures},
  year      = {2003},
  language  = {en}
}
@article{PietschBhattacharyaMukherjeeetal.2003,
  author    = {Pietsch, Ullrich and Bhattacharya, M. K. and Mukherjee, M. and Sanyal, M. K. and Geue, Thomas and Grenzer, J{\"o}rg},
  title     = {Energy dispersive x-ray reflectivity technique to study thermal properties of polymer films},
  year      = {2003},
  language  = {en}
}
@article{PietschGrigorianGrenzeretal.2003,
  author    = {Pietsch, Ullrich and Grigorian, Souren A. and Grenzer, J{\"o}rg and Feranchuk, S. and Zeimer, Ute},
  title     = {Grazing-incidence diffraction study of strain-modulated single quantum well nanostructures},
  year      = {2003},
  language  = {en}
}
@article{PietschPanznerLeitenbergeretal.2003,
  author    = {Pietsch, Ullrich and Panzner, Tobias and Leitenberger, Wolfram and Grenzer, J{\"o}rg and Bodenthin, Th. and Geue, Thomas and M{\"o}hwald, Helmuth},
  title     = {Coherence experiments at the energy-dispersive reflectometry beamline at BESSY II},
  year      = {2003},
  language  = {en}
}
@article{PietschGeueHennebergetal.2003,
  author    = {Pietsch, Ullrich and Geue, Thomas and Henneberg, Oliver and Saphiannikova, Marina},
  title     = {X-ray investigations of formation efficiency of buried azobenzene polymer density gratings},
  doi       = {10.1063/1.1554753},
  year      = {2003},
  language  = {en}
}
@article{Pietsch2003,
  author    = {Pietsch, Ullrich},
  title     = {Evidence of a density grating under light induced formation of surface relief gratings at polymers containing azobenzene moieties},
  year      = {2003},
  language  = {en}
}
@article{PietschGrigorianGrenzeretal.2003,
  author    = {Pietsch, Ullrich and Grigorian, Souren A. and Grenzer, J{\"o}rg and Vartanyants, Ivan A.},
  title     = {Thermal diffuse scattering in grazing incidence diffraction},
  year      = {2003},
  language  = {en}
}
@article{PietschTsirelsonGorfan2003,
  author    = {Pietsch, Ullrich and Tsirelson, Vladimir G. and Gorfan, S. V.},
  title     = {X-ray scattering amplitude of an atom in a permanent external electric field},
  year      = {2003},
  language  = {en}
}
@article{Pietsch2003,
  author    = {Pietsch, Ullrich},
  title     = {Thin Layers of columns of an amphiphilic hexa-peri-hexabenzocoronene at silicon wafer surfaces},
  year      = {2003},
  language  = {en}
}
@article{HennebergGeueSaphiannikovaetal.2003,
  author    = {Henneberg, Oliver and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich and Rochon, Paul},
  title     = {X-ray and VIS light scattering from light-induced polymer gratings},
  doi       = {10.1088/0022-3727/36/10A/350},
  year      = {2003},
  language  = {en}
}
@article{PietschLeitenbergerWendrocketal.2003,
  author    = {Pietsch, Ullrich and Leitenberger, Wolfram and Wendrock, Horst and Bischoff, Lothar and Panzner, Tobias and Grenzer, J{\"o}rg and Pucher, Andreas},
  title     = {Double pinhole diffraction of white synchrotron radiation},
  year      = {2003},
  language  = {en}
}
@article{PietschDavaasambuuPucheretal.2003,
  author    = {Pietsch, Ullrich and Davaasambuu, Jav and Pucher, Andreas and Kochin, V.},
  title     = {Atomistic origin of the inverse piezoelectric effect in alpha-SiO2 and alpha-GaPO4},
  issn      = {0295-5075},
  year      = {2003},
  language  = {en}
}
@article{PietschMukhopadhyaySanyaletal.2004,
  author    = {Pietsch, Ullrich and Mukhopadhyay, M. K. and Sanyal, M. K. and Datta, A. and Mukherjee, M. and Geue, Thomas and Grenzer, J{\"o}rg},
  title     = {Transition from two-dimensional to three-dimensional melting in Langmuir-Blodgett films},
  year      = {2004},
  abstract  = {Results of energy-dispersive x-ray reflectivity and grazing incidence diffraction studies of Langmuir-Blodgett films exhibited evolution of conventional three-dimensional melting from continuous melting, characteristic of two- dimensional systems, as a function of deposited monolayers. Continuous expansion followed by a sharp phase transition of the in-plane lattice was observed before the melting point and found to be independent of number of deposited layers. Evolution of conventional melting with an increase in the number of monolayers could be quantified by measuring stiffness against tilting of the vertical stack of molecules, which are kept together by an internal field. The internal field as defined in this model reduces as the in-plane lattice expands and the sample temperature approaches melting point. The sharpness of the melting transition, which has been approximated by a Langevin function, increases with the number of deposited monolayers},
  language  = {en}
}
@article{PietschDavaasambuuKochinetal.2004,
  author    = {Pietsch, Ullrich and Davaasambuu, Jav and Kochin, V. and Schwarz, K. H. and Blaha, Pawel},
  title     = {The atomistic origin of the inverse piezoelectric effect in a-quartz},
  year      = {2004},
  abstract  = {Ab initio calculations have been carried out using the FP-APW+lo method in order to understand the atomic origin of the inverse piezoelectric effect in x-quartz. The external electric field was modelled by a saw-like potential V-ext in order to achieve translational symmetry within a supercell (SC) containing 72 atoms. The original trigonal quartz structure was repeated along the [110] direction, which corresponds to the direction of the external field. An electric field with 550 kV/mm was applied and the atomic positions of the SC were relaxed until the forces acting on the atoms vanished. In parts of the SC, V-ext changes almost linearly and thus the relaxed atomic positions can be used to determine the structural response due to the external electric field. The calculations provide the piezoelectric modulus of the correct order of magnitude. In contrast to previous models and in agreement with recent experimental results, the atomic origin of the piezoelectric effect can be described by a rotation of slightly deformed SiO4 tetrahedra against each other. The change of the Si-O bond lengths and the tetrahedral O-Si-O angles is one order of magnitude smaller than that of the Si-O-Si angles between neighbouring tetrahedra. The calculated changes of X-ray structure factors are in agreement with experiment when the theoretical data are extrapolated down to the much smaller field strength that is applied in the experiment (E < 10 kV/mm). (C) 2004 Elsevier Ltd. All rights reserved},
  language  = {en}
}
@article{SaphiannikovaGeueHennebergetal.2004,
  author    = {Saphiannikova, Marina and Geue, Thomas and Henneberg, Oliver and Morawetz, Knut and Pietsch, Ullrich},
  title     = {Linear viscoelastic analysis of formation and relaxation of azobenzene polymer gratings},
  doi       = {10.1063/1.1642606},
  year      = {2004},
  abstract  = {Surface relief gratings on azobenzene containing polymer films were prepared under irradiation by actinic light. Finite element modeling of the inscription process was carried out using linear viscoelastic analysis. It was assumed that under illumination the polymer film undergoes considerable plastification, which reduces its original Young's modulus by at least three orders of magnitude. Force densities of about 10(11) N/m(3) were necessary to reproduce the growth of the surface relief grating. It was shown that at large deformations the force of surface tension becomes comparable to the inscription force and therefore plays an essential role in the retardation of the inscription process. In addition to surface profiling the gradual development of an accompanying density grating was predicted for the regime of continuous exposure. Surface grating development under pulselike exposure cannot be explained in the frame of an incompressible fluid model. However, it was easily reproduced using the viscoelastic model with finite compressibility. (C) 2004 American Institute of Physics},
  language  = {en}
}
@article{PietschJarreSaldittetal.2004,
  author    = {Pietsch, Ullrich and Jarre, A. and Salditt, T. and Panzner, Tobias and Pfeiffer, F.},
  title     = {White beam x-ray waveguide optics},
  year      = {2004},
  abstract  = {We report a white beam x-ray waveguide (WG) experiment. A resonant beam coupler x-ray waveguide (RBC) is used simultaneously as a broad bandpass (or multibandpass) monochromator and as a beam compressor. We show that, depending on the geometrical properties of the WG, the exiting beam consists of a defined number of wavelengths which can be shifted by changing the angle of incidence of the white x-ray synchrotron beam. The characteristic far-field pattern is recorded as a function of exit angle and energy. This x-ray optical setup may be used to enhance the intensity of coherent x-ray WG beams since the full energetic acceptance of the WG mode is transmitted. (C) 2004 American Institute of Physics},
  language  = {en}
}
@article{HennebergPanznerPietschetal.2004,
  author    = {Henneberg, Oliver and Panzner, Tobias and Pietsch, Ullrich and Geue, Thomas and Saphiannikova, Marina and Rochon, Paul and Finkelstein, Kenneth D.},
  title     = {X-ray and VIS light scattering from light-induced polymer gratings},
  issn      = {0044-2968},
  year      = {2004},
  abstract  = {Sinusoidally shaped surface relief gratings made of polymer films containing, azobenzene moieties can be created by holographic illumination with laser light of about lambda approximate to 500 nm. The remarkable material transport takes place at temperatures far (100 K) below the glass transition temperature of the material. As probed by visible light scattering the efficiency of grating formation crucially depends on the polarization state of the laser light and is maximal when circular polarization is used. In contrast to VIS light scattering X-ray diffraction is most sensitive for periodic surface undulations with amplitudes below 10 nm. Thus, combined in-situ X-ray and visible light scattering at CHESS were used to investigate the dynamics of surface relief grating formations upon laser illumination. The time development of grating peaks up to 9th order at laser power of P = 20 mW/cm(2) could be investigated, even the onset of grating formation as a function of light polarization. A linear growth of grating amplitude was observed for all polarizations. The growth velocity is maximal using circularly polarized light but very small for s-polarized light},
  language  = {en}
}
@article{HennebergGeuePietschetal.2004,
  author    = {Henneberg, Oliver and Geue, Thomas and Pietsch, Ullrich and Winter, Bernd},
  title     = {Investigation of azobenzene side group orientation in polymer surface relief gratings by means of photoelectron spectroscopy},
  year      = {2004},
  abstract  = {The molecular orientation of azobenzene side groups in polymer films before (nonpatterned) and after (patterned) development of a surface relief grating has been investigated by photoelectron spectroscopy using synchrotron radiation. The photoemission spectra obtained for 60-100 eV photons of a patterned and a nonpatterned surface are similar when the polarization vector of the synchrotron light is parallel to the grating vector. However, for perpendicular excitation, considerable spectral intensity differences can be observed for 9-14 eV electron binding energy. The observed changes are attributed to the formation of well-oriented azobenzenes at the surface. (C) 2004 American Institute of Physics},
  language  = {en}
}
@article{PietschHazraChinietal.2004,
  author    = {Pietsch, Ullrich and Hazra, S. and Chini, T. K. and Sanyal, M. K. and Grenzer, J{\"o}rg},
  title     = {Ripple structure of crystalline layers in ion beam induced Si wafers},
  year      = {2004},
  abstract  = {Ion-beam-induced ripple formation in Si wafers was studied by two complementary surface sensitive techniques, namely atomic force microscopy (AFM) and depth-resolved x-ray grazing incidence diffraction (GID). The formation of ripple structure at high doses (similar to7x10(17) ions/cm(2)), starting from initiation at low doses (similar to1x10(17) ions/cm(2)) of ion beam, is evident from AFM, while that in the buried crystalline region below a partially crystalline top layer is evident from GID study. Such ripple structure of crystalline layers in a large area formed in the subsurface region of Si wafers is probed through a nondestructive technique. The GID technique reveals that these periodically modulated wavelike buried crystalline features become highly regular and strongly correlated as one increases the Ar ion-beam energy from 60 to 100 keV. The vertical density profile obtained from the analysis of a Vineyard profile shows that the density in the upper top part of ripples is decreased to about 15\% of the crystalline density. The partially crystalline top layer at low dose transforms to a completely amorphous layer for high doses, and the top morphology was found to be conformal with the underlying crystalline ripple},
  language  = {en}
}