| First-Principles Calculations of Elasticity, Polarization-Related Properties, and Nonlinear Optical Coefficients in Zn-IV-N2 Compounds |
Jan 2009 |
7 pages |
| Authors:
Tula R Paudel; Walter R Lambrecht; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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 | The Zn-IV-N2 compounds with the group-IV elements Si, Ge, and Sn are a series of promising wide-band-gap semiconductors with estimated band gaps ranging from about 1 to possibly as large as 5 eV.(sup 1-3). As is the case for their III-N analogs, their relatively high ionicity implies that they are also potentially interesting piezoelectric materials and, according to their relatively low symmetry, should be pyroelectric, i.e., possess a nonzero spontaneous ... |
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| Magneto-Optical Properties of Hybrid Magnetic Material Semiconductor Nanostructures |
14 SEP 2007 |
12 pages |
| Authors:
Walter R. Lambrecht; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| First-principles calculations were performed of a variety of materials systems of potential interest in spintronics. A comprehensive study was made of transitional metal doping in SiC and their magnetic properties. The trends in magnetic properties and in the preference for rocksalt versus zincblende structure were studied for the entire series of transition metal nitrides. The LSDA+U method was implemented in the FP-LMTO approach and applied to rare-earth nitrides and related ... |
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| Computational Study of Chalcopyrite Semiconductors and Their Non-Linear Optical Properties |
12 SEP 2007 |
14 pages |
| Authors:
Walter R. Lambrecht; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| Electronic structure studies were carried out for chalcopyrite semiconductors with the aim of modeling their optical properties. The main results of the grant are : a comprehensive study of the Intrinsic point defects In ZnGeP2 (Including cation antisites, cation and anion vacancies) and CdGeAs2; a study of the feasibility of nonciritical phase matching and associated nonlinear optical parameters in CdSiP2 and CdSIAs2; a study of the band structure of defect ... |
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| Modelling of Wide-Band-Gap Semiconductor Alloys |
25 JUL 95 |
10 pages |
| Authors:
Walter R. Lambrecht; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| The grant studies the band gap bowing and miscibility in wide-band- gap nitride alloy systems by means of first principles LMTO calculations. Calculations were completed for Al(x)B(1-x)N and In(x)Ga(1-x)N ordered structures and disordered alloys using a cluster expansion approach. Bond- length relaxation effects on the energy of formation were investigated using a Keating model for Al(x)B(1-x)N. Their effects on the band-gap bowing were investigated for In(x)Ga(1-x)N. Band structure calculations were ... |
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| Thermal Relaxation Processes and Stability in Poled Electro-Optic Polymers |
30 JUN 94 |
8 pages |
| Authors:
Kenneth D. Singer; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| We have made important progress in the last year in modeling the decay of molecular orientation in poled electro-optic materials in order to more accurately predict the evolution of the nonlinear optical response over time and are approaching a predictive description of the long time scale orientational decay of poled polymer systems. The most remarkable feature of decay measurements of the nonlinear optical response is that it appears similar over ... |
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| Tensile Properties of Aluminum/Alumina Multi-Layered Thin Films. |
1993 |
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| Authors:
G. T. Mearini; R. W. Hoffman; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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 | This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, data, dr mmc, experimental, mmc materials and material types:, (al2o3)w/al, al matrix, al2o3 films, al2o3 whiskers, al2o3/al, whiskers material characteristics and data fields:, bulk modulus, grain boundary, mechanical behaviors, modulus data, stress-strain curves, stress-strain data, uts data, young's modulus testing and test conditions:, mechanical testing, rbs, sam, sem, tem, tensile tests ... |
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| A Comparison of the Wurtzite and Zincblende Band Structures for SiC, AlN and GaN |
92 |
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| Authors:
W. R. L. Lambrecht; B. Segall; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| Total energy and band structure results of linear-muffin-tin orbital calculations within the atomic-sphere-approximation are presented for SiC, GaN and AlN in the zincblende and the wurtzite structure. We discuss the origin of the directness or indirectness and the relative magnitudes of the band gaps. |
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| Polymeric Second-Order Nonlinear Optical Materials. |
1992 |
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| Authors:
D. Kenneth; CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| Copyright: American Copyright: American |
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| Nanomechanics of Thin Films |
JUN 90 |
9 pages |
| Authors:
CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF PHYSICS
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| The work on the nanomechanics of thin films and microfibriles and interfaces is proceeding in a three-pronged approach, concentrating on deposited films and interfaces. The goal was to examine the structure property relations for mechanical properties in aluminum and aluminum oxide multilayers. Briefly the aluminum films have been deposited in various thicknesses in UHV by evaporation from a W source and subsequently examined by AES, TEM and other surface analyses. ... |
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