@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{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{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{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{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{WegenerBergweilerWirgesetal.2005,
  author    = {Wegener, Michael and Bergweiler, Steffen and Wirges, Werner and Pucher, Andreas and Tuncer, Enis and Gerhard, Reimund},
  title     = {Piezoelectric two-layer stacks of cellular polypropylene ferroelectrets : transducer response at audio and ultrasound frequencies},
  issn      = {0885-3010},
  year      = {2005},
  abstract  = {Piezoelectric cellular polypropylene films, so-called ferroelectrets, are assembled in a stack with two active transducer layers. The stack is characterized with respect to its linear and quadratic response in a frequency range from 1 kHz to 80 kHz. A relatively smooth frequency response in the sound-pressure level is found for the individual layers as well as for both layers driven in phase. The piezoelectric response of the two-layer stack is twice the response of an individual layer over a rather broad frequency range. Furthermore, the influence of the preparation conditions on the resonance frequency and the effect of the quadratic distortion on the radiated sound are investigated both for the individual transducer films in the stack and for the stack system as a whole},
  language  = {en}
}
@article{KuenstlerXiaWeinholdetal.2000,
  author    = {K{\"u}nstler, Wolfgang and Xia, Zhongfu and Weinhold, Till and Pucher, Andreas and Gerhard, Reimund},
  title     = {Piezoelectricity of porous polytetrafluoroethylene single- and multiple-film electrets containing high charge densities of both polarities},
  year      = {2000},
  language  = {en}
}
@article{GerhardKuenstlerGoerneetal.2000,
  author    = {Gerhard, Reimund and K{\"u}nstler, Wolfgang and G{\"o}rne, Thomas and Pucher, Andreas and Weinhold, Till and Seiß, Martin and Xia, Zhongfu and Wedel, Armin and Danz, Rudi},
  title     = {Porous polytetrafluoroethylene space-charge electrets for piezoelectrical applications},
  year      = {2000},
  language  = {en}
}
@article{GerhardXiaKuenstleretal.1999,
  author    = {Gerhard, Reimund and Xia, Zhongfu and K{\"u}nstler, Wolfgang and Pucher, Andreas},
  title     = {Preliminary study of multi-layer space-charge electrets with piezoelectric properties from porous and non- porous Teflon films},
  year      = {1999},
  language  = {en}
}
@article{WegenerBergweilerWirgesetal.2004,
  author    = {Wegener, Michael and Bergweiler, Steffen and Wirges, Werner and Pucher, Andreas and Gerhard, Reimund},
  title     = {Voided space-charge electrets : piezoelectric transducer materials for electro-acoustic applications},
  year      = {2004},
  language  = {en}
}
@article{GorfmanTsirelsonPucheretal.2006,
  author    = {Gorfman, Semen and Tsirelson, Vladimir and Pucher, Andreas and Morgenroth, Wolfgang and Pietsch, Ullrich},
  title     = {X-ray diffraction by a crystal in a permanent external electric field : electric-field-induced structural response in alpha-GaPO4},
  issn      = {0108-7673},
  doi       = {10.1107/S0108767305036111},
  year      = {2006},
  abstract  = {For the first time, site-selective distortion has been investigated for two different structural units in the ternary compound alpha-GaPO4 under the influence of a permanent external electric field. Based on 54 measured reflection intensities, the electric-field-induced distortion of PO4 and GaO4 tetrahedra in alpha-GaPO4 crystals is evaluated using a model of pseudoatomic displacements introduced recently [Gorfman, Tsirelson \& Pietsch (2005). Acta Cryst. A61, 387- 396]. A stronger variation of the P-O bond lengths in the PO4 tetrahedron was found compared to the bonds in the GaO4 tetrahedron. The different distortions of the tetrahedra owing to the electric field were analysed in terms of the valence charge density of alpha-GaPO4 and its topological characteristics. The larger charge of the P pseudoatom compared to the Ga atom was recognized as the main reason for the higher sensitivity of the PO4 tetrahedron to a permanent external electric field},
  language  = {en}
}