TY  - JOUR
A1  - Zen, Achmad
A1  - Saphiannikova, Marina
A1  - Neher, Dieter
A1  - Asawapirom, Udom
A1  - Scherf, Ullrich
T1  - Comparative study of the field-effect mobility of a copolymer and a binary blend based on poly(3- alkylthiophene)s
N2  - The performance of highly soluble regioregular poly[ (3-hexylthiophene)-co-(3-octylthiophetie)] (P3HTOT) as a semiconducting material in organic field-effect transistors (OFETs) is presented in comparison to that of the corresponding homopolymers. Transistors made from as-prepared layers of P3HTOT exhibit a mobility of ca. 7 x 10(-3) cm(2) V-1 s(-1), which is comparable to the performance of transistors made from as-prepared poly(3-hexylthiophene) (P3HT) and almost 6 times larger than the mobility of transistors prepared with poly(3-octylthiophene) (P3OT). On the other hand, the solubility parameter delta(p) of P3HTOT is close to that of the highly soluble P3OT. Moreover, compared to a physical blend of poly(3-hexylthiophene) and poly(3-octylthiophene), the mobility of P3HTOT devices is almost twice as large and the performance does not degrade upon annealing at elevated temperatures. Therefore, the copolymer approach outlined here may be one promising step toward an optimum balance between a Sufficient processability of the polymers from common organic solvents, a high solid state order, and applicable OFET performances
Y1  - 2005
SN  - 0897-4756
ER  - 
TY  - JOUR
A1  - Zen, Achmad
A1  - Pflaum, J.
A1  - Hirschmann, S.
A1  - Zhuang, W.
A1  - Jaiser, Frank
A1  - Asawapirom, Udom
A1  - Rabe, J. P.
A1  - Scherf, Ullrich
A1  - Neher, Dieter
T1  - Effect of molecular weight and annealing of poly (3-hexylthiophene)s on the performance of organic field-effect transistors
N2  - The optical, structural, and electrical properties of thin layers made from poly(3-hexylthiophene) (P3HT) samples of different molecular weights are presented. As reported in a previous paper by Kline et al., Adv. Mater 2003, 15, 1519, the mobilities of these layers are a strong function of the molecular weight, with the largest mobility found for the largest molecular weight. Atomic force microscopy studies reveal a complex polycrystalline morphology which changes considerably upon annealing. X-ray studies show the occurrence of a layered phase for all P3HT fractions, especially after annealing at 1.50 degreesC . However, there is no clear correlation between the differences in the transport properties and the data from structural investigations. In order to reveal the processes limiting the mobility in these layers, the transistor properties were investigated as a function of temperature. The mobility decreases continuously with increasing temperatures; with the same trend pronounced thermochromic effects of the P3HT films occur. Apparently, the polymer chains adopt a more twisted, disordered conformation at higher temperatures, leading to interchain transport barriers. We conclude that the backbone conformation of the majority of the bulk material rather than the crystallinity of the layer is the most crucial parameter controlling the charge transport in these P3HT layers. This interpretation is supported by the significant blue-shift of the solid-state absorption spectra with decreasing molecular weight, which is indicative of a larger distortion of the P3HT backbone in the low-molecular weight P3HT layers
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Zen, Achmad
A1  - Neher, Dieter
A1  - Silmy, Kamel
A1  - Hollander, A.
A1  - Asawapirom, Udom
A1  - Scherf, Ullrich
T1  - Improving the performance of organic field effect transistor by optimizing the gate insulator surface
N2  - The effect of oxygen plasma treatment and/or silanization with hexamethyldisilazane (HMDS) on the surface chemistry and the morphology of the SiO2-gate insulator were studied with respect to the performance of organic field effect transistors. Using X-ray photoelectron spectroscopy (XPS), it is shown that silanization leads to the growth of a polysiloxane interfacial layer and that longer silanization times increase the thickness of this layer. Most important, silanization reduces the signal from surface contaminations such as oxidized hydrocarbon molecules. In fact, the lowest concentration of these contaminations was found after a combined oxygen plasma/silanization treatment. The results of these investigations were correlated with the characteristic device parameters of polymer field effect transistors with poly(3-hexylthiophene)s as the semiconducting layer. We found that the field effect mobility correlates with the concentration of contaminations as measured by XPS. We, finally, demonstrate that silanization significantly improves the operational stability of the device in air compared to the untreated devices
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Zen, Achmad
A1  - Neher, Dieter
A1  - Bauer, C.
A1  - Asawapirom, Udom
A1  - Scherf, Ullrich
A1  - Hagen, R.
A1  - Kostromine, S.
A1  - Mahrt, R. F.
T1  - Polarization-sensitive photoconductivity in aligned polyfluorene layers
Y1  - 2002
ER  - 
TY  - JOUR
A1  - Zen, Achmad
A1  - Bilge, Askin
A1  - Galbrecht, Frank
A1  - Alle, Ronald
A1  - Meerholz, Klaus
A1  - Grenzer, Jörg
A1  - Neher, Dieter
A1  - Scherf, Ullrich
A1  - Farrell, Tony
T1  - Solution processable organic field-effect transistors utilizing an alpha,alpha '-dihexylpentathiophene- based swivel cruciform
Y1  - 2006
UR  - http://pubs.acs.org/doi/full/10.1021/ja0573357
U6  - https://doi.org/10.1021/Ja0573357
ER  - 
TY  - JOUR
A1  - Zemanova, Lucia
A1  - Zhou, Changsong
A1  - Kurths, Jürgen
T1  - Structural and functional clusters of complex brain networks
JF  - Physica, D, Nonlinear phenomena
N2  - Recent research using the complex network approach has revealed a rich and complicated network topology in the cortical connectivity of mammalian brains. It is of importance to understand the implications of such complex network structures in the functional organization of the brain activities. Here we study this problem from the viewpoint of dynamical complex networks. We investigate synchronization dynamics on the corticocortical network of the cat by modeling each node (cortical area) of the network with a sub-network of interacting excitable neurons. We find that the network displays clustered synchronization behavior, and the dynamical clusters coincide with the topological community structures observed in the anatomical network. Our results provide insights into the relationship between the global organization and the functional specialization of the brain cortex.
KW  - cortical network
KW  - anatomical connectivity
KW  - functional connectivity
KW  - topological community
KW  - dynamical cluster
Y1  - 2006
U6  - https://doi.org/10.1016/j.physd.2006.09.008
SN  - 0167-2789
SN  - 1872-8022
VL  - 224
IS  - 1-2
SP  - 202
EP  - 212
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Zellmeier, M.
A1  - Brenner, Thomas J. K.
A1  - Janietz, Silvia
A1  - Nickel, N. H.
A1  - Rappich, J.
T1  - Polythiophenes as emitter layers for crystalline silicon solar cells
BT  - parasitic absorption, interface passivation, and open circuit voltage
JF  - Journal of applied physics
N2  - We investigated the influence of the emitter (amorphous-Si, a-Si, or polythiophene derivatives: poly(3-hexylthiophene), P3HT, and poly(3-[3,6-dioxaheptyl]-thiophene), P3DOT) and the interface passivation (intrinsic a-Si or SiOX and methyl groups or SiOX) on the c-Si based 1 × 1 cm2 planar hybrid heterojunction solar cell parameters. We observed higher short circuit currents for the P3HT or P3DOT/c-Si solar cells than those obtained for a-Si/c-Si devices, independent of the interface passivation. The obtained VOC of 659 mV for the P3DOT/SiOX/c-Si heterojunction solar cell with hydrophilic 3,6-dioxaheptyl side chains is among the highest reported for c-Si/polythiophene devices. The maximum power conversion efficiency, PCE, was 11% for the P3DOT/SiOX/c-Si heterojunction solar cell. Additionally, our wafer lifetime measurements reveal a field effect passivation in the wafer induced by the polythiophenes when deposited on c-Si.
Y1  - 2018
U6  - https://doi.org/10.1063/1.5006625
SN  - 0021-8979
SN  - 1089-7550
VL  - 123
IS  - 3
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Zeitz, Maria
A1  - Reese, Ronja
A1  - Beckmann, Johanna
A1  - Krebs-Kanzow, Uta
A1  - Winkelmann, Ricarda
T1  - Impact of the melt-albedo feedback on the future evolution of the Greenland Ice Sheet with PISM-dEBM-simple
JF  - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2  - Surface melting of the Greenland Ice Sheet contributes a large amount to current and future sea level rise. Increased surface melt may lower the reflectivity of the ice sheet surface and thereby increase melt rates: the so-called melt-albedo feedback describes this self-sustaining increase in surface melting. In order to test the effect of the melt-albedo feedback in a prognostic ice sheet model, we implement dEBM-simple, a simplified version of the diurnal Energy Balance Model dEBM, in the Parallel Ice Sheet Model (PISM). The implementation includes a simple representation of the melt-albedo feedback and can thereby replace the positive-degree-day melt scheme. Using PISM-dEBM-simple, we find that this feedback increases ice loss through surface warming by 60 % until 2300 for the high-emission scenario RCP8.5 when compared to a scenario in which the albedo remains constant at its present-day values. With an increase of 90 % compared to a fixed-albedo scenario, the effect is more pronounced for lower surface warming under RCP2.6. Furthermore, assuming an immediate darkening of the ice surface over all summer months, we estimate an upper bound for this effect to be 70 % in the RCP8.5 scenario and a more than 4-fold increase under RCP2.6. With dEBM-simple implemented in PISM, we find that the melt-albedo feedback is an essential contributor to mass loss in dynamic simulations of the Greenland Ice Sheet under future warming.
Y1  - 2021
U6  - https://doi.org/10.5194/tc-15-5739-2021
SN  - 1994-0416
SN  - 1994-0424
VL  - 15
IS  - 12
SP  - 5739
EP  - 5764
PB  - Copernicus
CY  - Katlenburg-Lindau
ER  - 
TY  - JOUR
A1  - Zeitz, Maria
A1  - Levermann, Anders
A1  - Winkelmann, Ricarda
T1  - Sensitivity of ice loss to uncertainty in flow law parameters in an idealized one-dimensional geometry
JF  - The Cryosphere : TC ; an interactive open access journal of the European Geosciences Union
N2  - Acceleration of the flow of ice drives mass losses in both the Antarctic and the Greenland Ice Sheet. The projections of possible future sea-level rise rely on numerical ice-sheet models, which solve the physics of ice flow, melt, and calving. While major advancements have been made by the ice-sheet modeling community in addressing several of the related uncertainties, the flow law, which is at the center of most process-based ice-sheet models, is not in the focus of the current scientific debate. However, recent studies show that the flow law parameters are highly uncertain and might be different from the widely accepted standard values. Here, we use an idealized flow-line setup to investigate how these uncertainties in the flow law translate into uncertainties in flow-driven mass loss. In order to disentangle the effect of future warming on the ice flow from other effects, we perform a suite of experiments with the Parallel Ice Sheet Model (PISM), deliberately excluding changes in the surface mass balance. We find that changes in the flow parameters within the observed range can lead up to a doubling of the flow-driven mass loss within the first centuries of warming, compared to standard parameters. The spread of ice loss due to the uncertainty in flow parameters is on the same order of magnitude as the increase in mass loss due to surface warming. While this study focuses on an idealized flow-line geometry, it is likely that this uncertainty carries over to realistic three-dimensional simulations of Greenland and Antarctica.
Y1  - 2020
U6  - https://doi.org/10.5194/tc-14-3537-2020
SN  - 1994-0416
SN  - 1994-0424
VL  - 14
IS  - 10
SP  - 3537
EP  - 3550
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Zeitz, Maria
A1  - Haacker, Jan M.
A1  - Donges, Jonathan
A1  - Albrecht, Torsten
A1  - Winkelmann, Ricarda
T1  - Dynamic regimes of the Greenland Ice Sheet emerging from interacting melt-elevation and glacial isostatic adjustment feedbacks
JF  - Earth system dynamics
N2  - The stability of the Greenland Ice Sheet under global warming is governed by a number of dynamic processes and interacting feedback mechanisms in the ice sheet, atmosphere and solid Earth. 
Here we study the long-term effects due to the interplay of the competing melt-elevation and glacial isostatic adjustment (GIA) feedbacks for different temperature step forcing experiments with a coupled ice-sheet and solid-Earth model. 
Our model results show that for warming levels above 2 degrees C, Greenland could become essentially ice-free within several millennia, mainly as a result of surface melting and acceleration of ice flow. These ice losses are mitigated, however, in some cases with strong GIA feedback even promoting an incomplete recovery of the Greenland ice volume. We further explore the full-factorial parameter space determining the relative strengths of the two feedbacks: our findings suggest distinct dynamic regimes of the Greenland Ice Sheets on the route to destabilization under global warming - from incomplete recovery, via quasi-periodic oscillations in ice volume to ice-sheet collapse. 
In the incomplete recovery regime, the initial ice loss due to warming is essentially reversed within 50 000 years, and the ice volume stabilizes at 61 %-93 % of the present-day volume. For certain combinations of temperature increase, atmospheric lapse rate and mantle viscosity, the interaction of the GIA feedback and the melt-elevation feedback leads to self-sustained, long-term oscillations in ice-sheet volume with oscillation periods between 74 000 and over 300 000 years and oscillation amplitudes between 15 %-70 % of present-day ice volume. 
This oscillatory regime reveals a possible mode of internal climatic variability in the Earth system on timescales on the order of 100 000 years that may be excited by or synchronized with orbital forcing or interact with glacial cycles and other slow modes of variability. Our findings are not meant as scenario-based near-term projections of ice losses but rather providing insight into of the feedback loops governing the "deep future" and, thus, long-term resilience of the Greenland Ice Sheet.
Y1  - 2022
U6  - https://doi.org/10.5194/esd-13-1077-2022
SN  - 2190-4979
SN  - 2190-4987
VL  - 13
IS  - 3
SP  - 1077
EP  - 1096
PB  - Copernicus Publ.
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Zeiske, Stefan
A1  - Sandberg, Oskar J.
A1  - Zarrabi, Nasim
A1  - Wolff, Christian Michael
A1  - Raoufi, Meysam
A1  - Peña-Camargo, Francisco
A1  - Gutierrez-Partida, Emilio
A1  - Meredith, Paul
A1  - Stolterfoht, Martin
A1  - Armin, Ardalan
T1  - Static disorder in lead halide perovskites
JF  - The journal of physical chemistry letters
N2  - In crystalline and amorphous semiconductors, the temperature-dependent Urbach energy can be determined from the inverse slope of the logarithm of the absorption spectrum and reflects the static and dynamic energetic disorder. Using recent advances in the sensitivity of photocurrent spectroscopy methods, we elucidate the temperature-dependent Urbach energy in lead halide perovskites containing different numbers of cation components. We find Urbach energies at room temperature to be 13.0 +/- 1.0, 13.2 +/- 1.0, and 13.5 +/- 1.0 meV for single, double, and triple cation perovskite. Static, temperature-independent contributions to the Urbach energy are found to be as low as 5.1 ?+/- 0.5, 4.7 +/- 0.3, and 3.3 +/- 0.9 meV for the same systems. Our results suggest that, at a low temperature, the dominant static disorder in perovskites is derived from zero-point phonon energy rather than structural disorder. This is unusual for solution-processed semiconductors but broadens the potential application of perovskites further to quantum electronics and devices.
KW  - Cations
KW  - External quantum efficiency
KW  - Perovskites
KW  - Solar cells
KW  - Solar energy
Y1  - 2022
U6  - https://doi.org/10.1021/acs.jpclett.2c01652
SN  - 1948-7185
VL  - 13
IS  - 31
SP  - 7280
EP  - 7285
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Zeiske, Stefan
A1  - Sandberg, Oskar J.
A1  - Kurpiers, Jona
A1  - Shoaee, Safa
A1  - Meredith, Paul
A1  - Armin, Ardalan
T1  - Probing charge generation efficiency in thin-film solar cells by integral-mode transient charge extraction
JF  - ACS photonics
N2  - The photogeneration of free charges in light-harvesting devices is a multistep process, which can be challenging to probe due to the complexity of contributing energetic states and the competitive character of different driving mechanisms. In this contribution, we advance a technique, integral-mode transient charge extraction (ITCE), to probe these processes in thin-film solar cells. ITCE combines capacitance measurements with the integral-mode time-of-flight method in the low intensity regime of sandwich-type thin-film devices and allows for the sensitive determination of photogenerated charge-carrier densities. We verify the theoretical framework of our method by drift-diffusion simulations and demonstrate the applicability of ITCE to organic and perovskite semiconductor-based thin-film solar cells. Furthermore, we examine the field dependence of charge generation efficiency and find our ITCE results to be in excellent agreement with those obtained via time-delayed collection field measurements conducted on the same devices.
KW  - charge generation
KW  - thin-film solar cells
KW  - organic semiconductors;
KW  - perovskite semiconductors
KW  - external generation efficiency
Y1  - 2022
U6  - https://doi.org/10.1021/acsphotonics.1c01532
SN  - 2330-4022
VL  - 9
IS  - 4
SP  - 1188
EP  - 1195
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Zeimer, Ute
A1  - Pietsch, Ullrich
A1  - Grenzer, Joerg
A1  - Fricke, J.
A1  - Knauer, A.
A1  - Weyers, Markus
T1  - Optimised two layer overgrowth of a lateral strain-modulated nanostructure
N2  - Recently it has been shown that lateral carrier confinement in an InGaAs quantum well (QW) embedded in GaAs can be achieved by using a laterally patterned InGaP stressor layer on top of the heterostructure. To exploit this effect in a device the structure has to be planarized by a second epitaxial step. It has been shown that the lateral strain modulation almost vanishes after overgrowth with GaAs, whereas overgrowth with a single ternary layer of opposite strain compared to the stressor layer suffers from strain induced decomposition. Here we show that the lateral carrier confinement of the initially free standing nanostructure can almost be maintained using a two step process for overgrowth, where a strained thin ternary layer is grown first followed by GaAs up to complete planarization of the patterned structure. Thickness and composition of the ternary layer are adjusted on the basis of finite element calculations of the strain distribution (FEM). The strain field achieved after overgrowth is probed by X-ray grazing- incidence diffraction (GID). (c) 2005 Elsevier B.V. All rights reserved
Y1  - 2005
SN  - 0925-8388
ER  - 
TY  - JOUR
A1  - Zeimer, Ute
A1  - Grenzer, Jörg
A1  - Pietsch, Ullrich
A1  - Bugge, F.
A1  - Smirnitzki, V.
A1  - Weyers, Markus
T1  - Investigation of strain-modulated InGaAs-nanostructures by grazing-incidence x-ray diffraction and photoluminescence
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Zeimer, Ute
A1  - Bugge, F.
A1  - Gramlich, S.
A1  - Smirnitzki, V.
A1  - Weyers, Markus
A1  - Tränkle, G.
A1  - Grenzer, Jörg
A1  - Pietsch, Ullrich
A1  - Cassabois, G.
A1  - Emiliani, V.
A1  - Linau, Christoph
T1  - Evidence of strain-induced lateral carrier confinement in InGaAs-quantum wells by low-temperature near-field spectroscopy
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Zeimer, Ute
A1  - Bugge, F.
A1  - Gramlich, S.
A1  - Smirnitzki, V.
A1  - Weyers, Markus
A1  - Tränkle, G.
A1  - Grenzer, Jörg
A1  - Pietsch, Ullrich
A1  - Cassabois, G.
A1  - Emiliani, V.
A1  - Lienau, C.
T1  - Evidence for strain-induced lateral carrier confinement in InGaAs quantum wells by low-temperature near-field spectroscopy
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zeimer, Ute
A1  - Baumbach, Tilo
A1  - Grenzer, Jörg
A1  - Lübbert, Daniel
A1  - Mazuelas, A.
A1  - Pietsch, Ullrich
A1  - Erbert, G.
T1  - 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
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Zehbe, Rolf
A1  - Zehbe, Kerstin
T1  - Strontium doped poly-epsilon-caprolactone composite scaffolds made by reactive foaming
JF  - The European journal of the history of economic thought
N2  - In the reconstruction and regeneration of bone tissue, a primary goal is to initiate bone growth and to stabilize the surrounding bone. In this regard, a potentially useful component in biomaterials for bone tissue engineering is strontium, which acts as cationic active agent, triggering certain intracellular pathways and acting as so called dual action bone agent which inhibits bone resorption while stimulating bone regeneration. In this study we established a novel processing for the foaming of a polymer (poly-epsilon-caprolactone) and simultaneous chemical reaction of a mixture of calcium and strontium hydroxides to the respective carbonates using supercritical carbon dioxide. The resultant porous composite scaffold was optimized in composition and strontium content and was characterized via different spectroscopic (infrared and Raman spectroscopy, energy dispersive X-ray spectroscopy), imaging (SEM, mu CT), mechanical testing and in vitro methods (fluorescence vital staining, MTT-assay). As a result, the composite scaffold showed good in vitro biocompatibility with partly open pore structure and the expected chemistry. First mechanical testing results indicate sufficient mechanical stability to support future in vivo applications. (C) 2016 Elsevier B.V. All rights reserved.
KW  - Strontium
KW  - Poly-epsilon-caprolactone
KW  - Porous scaffold
KW  - CAL-72 osteoblasts
KW  - L-929 fibroblasts
KW  - Reactive foaming
KW  - mu CT imaging
KW  - Spectroscopy
Y1  - 2016
U6  - https://doi.org/10.1016/j.msec.2016.05.045
SN  - 0928-4931
SN  - 1873-0191
VL  - 67
SP  - 259
EP  - 266
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Zehbe, Rolf
A1  - Zaslansky, Paul
A1  - Mochales, Carolina
A1  - Mueller, Wolf-Dieter
A1  - Fleck, Claudia
T1  - Synchrotron micro tomographic evaluation of multilayered zirconia ceramics-Volumetric effects after indentation
JF  - Journal of the European Ceramic Society
N2  - Electrophoretic deposition was used to produce zirconia specimen consisting of alternating layers of fully stabilized cubic zirconia and partially stabilized tetragonal zirconia. In this configuration, the tetragonal stabilized zirconia layers can undergo transformation toughening upon mechanical induced stresses, while the cubic stabilized layers can act as confining element. To understand the volumetric changes due to transformation toughening in these layered materials after indentation, we used an advanced synchrotron-based X-ray mu CT setup and compared the results with surface sensitive methods like Raman spectroscopy, AFM and white light interferometry. The high spatial resolution and the adapted beam energy between the absorption edges of zirconia and yttria allowed discriminating between individual layers due to differences in their yttria content. Furthermore we were able to identify single indents and link volume changes to different physical effects in the different stabilized zirconia parts and visualize the three dimensional volume around only few micrometre sized indents. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Yttria stabilized zirconia multilayers
KW  - X-ray mu CT
KW  - Electrophoretic deposition
KW  - Transformation toughening
Y1  - 2016
U6  - https://doi.org/10.1016/j.jeurceramsoc.2015.09.015
SN  - 0955-2219
SN  - 1873-619X
VL  - 36
SP  - 171
EP  - 177
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Zehbe, Rolf
A1  - Mochales, Carolina
A1  - Radzik, Daniela
A1  - Mueller, Wolf-Dieter
A1  - Fleck, Claudia
T1  - Electrophoretic deposition of multilayered (cubic and tetragonal stabilized) zirconia ceramics for adapted crack deflection
JF  - Journal of the European Ceramic Society
N2  - The electrophoretic deposition process was used to produce multi-layered ceramics consisting of alternating layers of fully stabilized cubic zirconia and partially stabilized tetragonal zirconia to make use of their different mechanical behaviour, investigating the possibility to deflect advancing cracks at the interfaces of the different layers. This crack deflection is apparently impacted by a toughening mechanism only found in the tetragonal stabilized zirconia polymorph and is characterized by the stress induced transformation of the metastable tetragonal phase into the monoclinic one, which is accompanied by a volume increase resulting in a closing mechanism for advancing cracks. While improving the electrophoretic deposition process, we investigated the transformation toughening mechanism at the layer interfaces and their effect on crack propagation. Investigations involved a combination of different imaging methods, including light microscopy, white light interferometry, atomic force microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and Raman spectroscopy. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Electrophoretic deposition
KW  - Yttria stabilized zirconia
KW  - Transformation toughening
KW  - Multilayer
KW  - Crack deflection
Y1  - 2016
U6  - https://doi.org/10.1016/j.jeurceramsoc.2015.08.022
SN  - 0955-2219
SN  - 1873-619X
VL  - 36
SP  - 357
EP  - 364
PB  - Elsevier
CY  - Oxford
ER  -