Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Using coherent x-ray speckle metrology, we have measured the influence of disorder on major loop return point memory (RPM) and complementary point memory (CPM) for a series of perpendicular anisotropy Co/Pt multilayer films. In the low disorder limit, the domain structures show no memory with field cycling--no RPM and…
Diluted magnetic semiconductors currently attract immense experimental and theoretical attention as one of the most promising classes of materials for spintronic applications. We report a detailed density-functional-theory study of the influence of the clustering of the substitutional Mn impurities on the electronic s…
The crystal structures of M 1+ x V 3 O 8 , where M 1+ x = Ag 1.229 and Na 1.164 , isomorphous to the Li 1+ x V 3 O 8 insertion electrode have been determined with x-ray four-circle diffraction. The networks of V ions are similar to each other, but significant differences for the M–O and M–M distances exist. The presen…
This paper presents an approach for the thermal control of an artificial anal sphincter using shape memory alloys. An artificial anal sphincter has been proposed by the authors to resolve problems of severe fecal incontinence in patients. The basic design of the artificial sphincter consists of two all-round shape mem…
Ceramics in the (BiMnO 3 ) x –(PbTiO 3 ) 1− x series were fabricated with compositions in the range . A macroscopically pseudocubic structure was observed for compositions x >0.4 while at x <0.4 the structure is tetragonal. The presence of a pseudocubic structure is attributed to frustration between different preferre…
We have used density functional pseudopotential calculations and molecular dynamics to predict new carbon structures of high stability. The new phases are strongly bound and involve the smallest radius nanotubes. It was found that it is possible to covalently link smallest/larger, smallest/smallest radius nanotubes to…
It is of high fundamental and practical importance to be able to control the formation and stability of the different crystalline phases of alumina (Al 2 O 3 ). In this study, we have used density functional theory methods to investigate the changes induced in the thermodynamically stable α phase and the metastable θ…
We theoretically investigate under what conditions the director field in a spindle-shaped nematic droplet or tactoid obtains a twisted, parity-broken structure. By minimizing the sum of the bulk elastic and surface energies, we show that a twisted director field is stable if the twist and bend elastic constants are sm…
Resonant Raman studies of compositional and size dispersion of CdS1−xSex nanocrystals in a glass matrix, Azhniuk, Yu M, Milekhin, A G, Gomonnai, A V, Lopushansky, V V, Yukhymchuk, V O, Schulze, S, Zenkevich, E I, Zahn, D R T
The changes in the dielectric constant of perovskite BiMnO 3 at about T C , which are induced by the magnetic ordering as well as by the application of magnetic fields, indicate that coupling exists between the magnetism and the dielectric properties. The soft-mode theory based on the single-well potential model and t…
In this paper a tuned vibration absorber (TVA) is realized using shape memory alloy (SMA) elements. The elastic modulus of SMA changes with temperature and this effect is exploited to develop a continuously tunable device. A TVA with beam elements is described, a simple two-degree-of-freedom model developed and the TV…
We have proposed the phenomenological description of dielectric hysteresis loops in ferroelectric semiconductors with charged defects and prevailing extrinsic conductivity. We have modified the Landau–Ginsburg approach and shown that the macroscopic state of the aforementioned inhomogeneous system can be described by…
We present a model for the leakage current in ferroelectric thin- film capacitors which explains two of the observed phenomena that have escaped satisfactory explanation, i.e. the occurrence of either a plateau or negative differential resistivity at low voltages, and the observation of a Positive Temperature Coeffici…
Cadmium selenide (CdSe) thin films were deposited on a glass substrate using the chemical bath deposition method at room temperature. The films were deposited using cadmium acetate as a Cd 2+ ion source and sodium selenosulfate as a Se 2− ion source. The ‘as-deposited’ CdSe thin films are red in colour and specularly…
The atomic structures of clean and hydrogen-adsorbed Pd(001) are investigated by low energy electron diffraction (LEED) I/V analysis. Clean Pd(001) shows little surface relaxation in sharp contrast to previous reports. Adsorbing 1 monolayer of hydrogen on Pd(001), we observe sizable expansion of the interlayer spacing…
It has been shown that the geometric Berry-phase shift acquired by the components of the light hole (LH) spinor during an adiabatic collision is equal to the angular distance traveled by the wave vector. For LH, geometric dephasing leads to equality between angular and crystal momentum relaxation time. I will show tha…
The reversible dephosphorylation of beta-aspartyl phosphate to L-aspartate-beta-semialdehyde (ASA) in the aspartate biosynthetic pathway is catalyzed by aspartate-beta-semialdehyde dehydrogenase (ASADH). The phosphate that is present to activate the aspartate carboxyl group is held in a separate and distinct binding s…
Abstract Tetragonal 0.88Pb(Zn 1/3 Nb 2/3 )O 3 –0.12PbTiO 3 (PZNT12) single crystals were found to possess high electromechanical coupling k 33 ∼ 86–88% and large coercive field ∼8 kV/cm, while exhibiting good temperature stability till its Curie temperature ( T C ) ∼190 °C. The role of dopants on the dielectric and pi…
The growth kinetics of passive films on iron and stainless steel (Fe−16.31%Cr) substrates in pH 8.4 borate buffer solution was investigated by using in situ specular X-ray reflectivity. The oxide growth rate decays exponentially with increasing oxide thickness consistent with the point defect model in which the electr…
The assignments of bands in the electronic spectra of Y 2 O 3:Er 3+ to Er 3+ ions situated at S 6 symmetry sites (Silver, J.; Martinez-Rubio, M. I.; Ireland, T. G.; Withnall, R. J. Phys. Chem. B 2001, 105, 7200; Silver, J.; Martinez-Rubio, M. I.; Ireland, T. G.; Fern, G. R.; Withnall, R. J. Phys. Chem. B 2001, 105, 94…