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Full-Text Articles in Physics
Imaging And Engineering The Nanoscale-Domain Structure Of A Sr0.61Ba0.39Nb2O6 Crystal Using A Scanning Force Microscope, K. Terabe, S. Takekawa, M. Nakamura, K. Kitamura, Alexei Gruverman
Imaging And Engineering The Nanoscale-Domain Structure Of A Sr0.61Ba0.39Nb2O6 Crystal Using A Scanning Force Microscope, K. Terabe, S. Takekawa, M. Nakamura, K. Kitamura, Alexei Gruverman
Alexei Gruverman Publications
We have investigated the ferroelectric domain structure formed in a Sr0.61Ba0.39Nb2O6 single crystal by cooling the crystal through the Curie point. Imaging the etched surface structure using a scanning force microscope (SFM) in both the topographic mode and the piezoresponse mode revealed that a multidomain structure of nanoscale island-like domains was formed. The island-like domains could be inverted by applying an appropriate voltage using a conductive SFM tip. Furthermore, a nanoscale periodically inverted-domain structure was artificially fabricated using the crystal which underwent poling treatment.
Nanoscale Observation Of Photo-Induced Domain Pinning And Investigation Of Imprint Behavior In Ferroelectric Thin Films, Alexei Gruverman, B. J. Rodriguez, R. J. Nemanich, A. I. Kingon
Nanoscale Observation Of Photo-Induced Domain Pinning And Investigation Of Imprint Behavior In Ferroelectric Thin Films, Alexei Gruverman, B. J. Rodriguez, R. J. Nemanich, A. I. Kingon
Alexei Gruverman Publications
Piezoresponse force microscopy has been used to investigate the nanoscale mechanism of imprint behavior of ferroelectric PbTiO3 thin films by studying the photoinduced changes in the hysteresis loops of individual grains. Illumination of the film with UV light resulted in a voltage shift opposite to that observed in ferroelectric thin film capacitors. This effect is attributed to the generation of an electric field within the surface dielectric layer as a result of the interaction between photo-induced charges and polarization charges. Application of a small non-switching bias to the film with simultaneous UV illumination resulted in domain pinning in …
Piezoresponse Force Microscopy For Polarity Imaging Of Gan, B.J. Rodriguez, Alexei Gruverman, A. I. Kingon, R. J. Nemanich
Piezoresponse Force Microscopy For Polarity Imaging Of Gan, B.J. Rodriguez, Alexei Gruverman, A. I. Kingon, R. J. Nemanich
Alexei Gruverman Publications
The polarity distribution of GaN based lateral polarity heterostructures is investigated by piezoresponse force microscopy (PFM). Simultaneous imaging of surface morphology, as well as the phase and magnitude of the piezoelectric response, is performed by PFM on a GaN film with patterned polarities on a c-Al2O3 substrate. We demonstrate that the polarity distribution of GaN based lateral polarity heterostructures can be deduced from the phase image of the piezoresponse with nanometer scale spatial resolution.
Coercive Fields In Ferroelectrics: A Case Study In Lithium Niobate And Lithium Tantalate`, Sungwon Kim, Venkatraman Gopalan, Alexei Gruverman
Coercive Fields In Ferroelectrics: A Case Study In Lithium Niobate And Lithium Tantalate`, Sungwon Kim, Venkatraman Gopalan, Alexei Gruverman
Alexei Gruverman Publications
The experimentally measured coercive electric fields for domain reversal in ferroelectrics are typically many orders of magnitude lower than the estimates from phenomenological free-energy theory. This letter specifically investigates the influence of polarization gradients at pre-existing 180° domain walls in ferroelectrics on coercive fields for domain wall motion. It is shown that the ratio of theoretical coercive field without and with a preexisting domain wall is directly proportional to the ratio xo /a, where a is the lattice parameter and 2xo is the polarization wall width. This factor is 7.5–45 for a 20–120 nm wall width, the latter …