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Full-Text Articles in Physics

Interfacial Coherency And Ferroelectricity Of Batio3/Srtio3 Superlattice Films, Y. L. Li, S. Y. Hu, Dmitri Tenne, A. Soukiassian, D. G. Schlom, X. X. Xi, K. J. Choi Dec 2007

Interfacial Coherency And Ferroelectricity Of Batio3/Srtio3 Superlattice Films, Y. L. Li, S. Y. Hu, Dmitri Tenne, A. Soukiassian, D. G. Schlom, X. X. Xi, K. J. Choi

Physics Faculty Publications and Presentations

We studied the phase transitions, domain morphologies, and polarizations in BaTiO3/SrTiO3 superlattices grown on SrTiO3 substrates. Using the phase field approach, we discovered the remarkable influence of film/substrate interfacial coherency on the ferroelectricity of the SrTiO3 layers within a superlattice: it is an orthorhombic ferroelectric for an incoherent interface while it exhibits only induced polarization by the adjacent BaTiO3 layers for a coherent interface. We presented the domain morphologies within individual BaTiO3 and SrTiO3 layers which have different ferroelectric symmetries. The results are compared to ultraviolet Raman spectroscopy and variable temperature x-ray …


The Challenge Of Understanding Radical Constructivism, Dewey I. Dykstra Jan 2007

The Challenge Of Understanding Radical Constructivism, Dewey I. Dykstra

Physics Faculty Publications and Presentations

Purpose: This contribution to the Festschrift honoring Ernst von Glasersfeld gives some insight into the perpetual problem of understanding radical constructivism (RC). Parallels with the Middle Way school of Buddhism appear to shed light on this challenge. Conclusions: The hegemony realism has over the thinking of even the most highly educated in our civilization plays a major role in their failure to understand RC. Those still subject to realism in their thinking interpret statements by those in RC in ways incompatible with RC. Until realists disequilibrate over mismatches between realist expectations and experiences, no alternative way of thinking is accessible …


“Once More Into The Breech…”, Dewey I. Dykstra Jan 2007

“Once More Into The Breech…”, Dewey I. Dykstra

Physics Faculty Publications and Presentations

No abstract provided.


Raman Study Of Oxygen Reduced And Re-Oxidized Strontium Titanate, Dmitri Tenne, I. E. Gonenli, A. Soukiassian, D. G. Schlom, S. M. Nakhmanson, K. M. Rabe, X. X. Xi Jan 2007

Raman Study Of Oxygen Reduced And Re-Oxidized Strontium Titanate, Dmitri Tenne, I. E. Gonenli, A. Soukiassian, D. G. Schlom, S. M. Nakhmanson, K. M. Rabe, X. X. Xi

Physics Faculty Publications and Presentations

We report Raman study of oxygen-reduced single crystal strontium titanate. Oxygen reduction leads to the appearance of the forbidden first order Raman peaks, as well as new spectral features attributed to the local vibrational modes associated with oxygen vacancies. This assignment is supported by ab initio calculations of phonon modes in SrTiO3 with introduced oxygen vacancies. Raman studies of re-oxidized samples show the same spectra as the initial single crystals. Comparison of Raman spectra of SrTiO3 thin films and reduced SrTiO3 single crystals demonstrates the importance of other factors such as polar grain boundaries in the lattice …