Chinese Physics Letters
The electron paramagnetic resonance spectra of trigonal Mn(2+) centers in ZnNbOF(5)center dot 6(H(2)O) and CoNbOF(5)center dot 6(H(2)O) crystals are studied on the basis of the complete energy matrices for a d(5) configuration ion in a trigonal ligand field. It is demonstrated that the local lattice structure around a trigonal Mn(2+) center has an elongation distortion along the crystalline c(3) axis, and when Mn(2+) is doped in the ZnNbOF(5)center dot 6(H(2)O) and CoNbOF(5)center dot 6(H(2)O) crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters for trigonal Mn(2+) centers in ZnNbOF(5)center dot 6(H(2)O) and CoNbOF(5)center dot 6(H(2)O) are determined.
关键词:
phase-transition;ions;complexes;crystals;spectra;fe-3+;epr
Physica B-Condensed Matter
On the basis of the defect model of trigonal Dy3+-O2- center in CaF2, the EPR parameters (g factors and hyperfine structure constants) for this trigonal center are calculated from the perturbation formulas. In the formulas, the contributions to EPR parameters due to the J-mixing among H-6(J) (J = 15/2, 13/2 and 11/2) states, the mixtures among the states with the same J-value and those between the lowest Kramers doublet Gamma(gamma) and other Kramers doublets Gamma(X) are included. In the calculation, the crystal field parameters are estimated from the superposition model. From the calculation, the EPR g factors g(\\), g(perpendicular to) are reasonably explained and the superposition model intrinsic parameters (A) over bar (2)(F-) and (A) over bar (2) (O2-) with R = 2.366 Angstrom are obtained. (C) 2003 Elsevier B.V. All rights reserved.
关键词:
EPR parameters;crystal-field theory;superposition model;Dy3+;CaF2;electron-paramagnetic-resonance;field parameters;single-crystals;ions
International Journal of Thermophysics
This paper discusses the short-pulse-flash method developed for thermal diffusivity measurements on thin films. Two kinds of CVD diamond film have been prepared, and their thermal diffusivity in the perpendicular direction has been measured with this method. The measurement errors caused by the surface coating are discussed.
关键词:
diamond;film;flash method;thermal diffusivity
Journal of Materials Research
A method is introduced to determine the depth distribution of the residual stresses in (Ti,Al)N films. The films were gradually stripped by chemical corrosion, an optical system was designed to test the curvature change of the specimens, and the depth distribution of the residual stresses was calculated. The results show that the residual stresses increase gradually from the interface of film/substrate and reach a maximum value at the middle region, then decrease until the surface.
关键词:
x-ray-diffraction;thin-films;coatings;performance;steel
