By using the superposition model,the tetragonal field parameters Ds and Dt are calculated from the structural data of（TiO6）9- cluster in SrTiO3 crystal.Based on these values,the EPR g factors of the rhombic Ti3+ cen...By using the superposition model,the tetragonal field parameters Ds and Dt are calculated from the structural data of（TiO6）9- cluster in SrTiO3 crystal.Based on these values,the EPR g factors of the rhombic Ti3+ center in SrTiO3 are calculated by use of only one adjustable parameter.The results show good agreement with the observed values.展开更多
为制备具有电容和压敏特性的 Sr Ti O3双功能器件 ,以 Sr(NO3) 2 ,Ti(OC4 H9) 4为原料 ,用溶胶 -凝胶方法制备 Sr Ti O3材料 ,研究了水和醋酸等对 Sr Ti O3材料的影响机理 ,并对其进行 X-射线衍射、红外光谱和 TEM分析 ,证明该薄膜为纳...为制备具有电容和压敏特性的 Sr Ti O3双功能器件 ,以 Sr(NO3) 2 ,Ti(OC4 H9) 4为原料 ,用溶胶 -凝胶方法制备 Sr Ti O3材料 ,研究了水和醋酸等对 Sr Ti O3材料的影响机理 ,并对其进行 X-射线衍射、红外光谱和 TEM分析 ,证明该薄膜为纳米晶体结构 ,晶粒尺寸为 1 2～ 2 5nm。展开更多
By using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix at normal and various pressures,the g factor of the ground state of SrTiO3:Cr^3+ and its pressure-induced shift have been microscop...By using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix at normal and various pressures,the g factor of the ground state of SrTiO3:Cr^3+ and its pressure-induced shift have been microscopically calculated.Only by taking the local strains around Cr^3+ in SrTiO3:Cr^3+(which are about twice the bulk ones)and corresponding P-χ dependence,can we obtain a good agreement etween the calculated result of pressure-induced shift of ground-state g factor and the experimental one.The physical origins of this pressure-induced shift have been explained.It is found that the change of Dq^-1 with pressure makes main contribution to the pressure-induced shift of ground-state g factor of SrTiO3:Cr^3+.By using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix at normal pressure,the relevant matrix elements and accordingly strain-induced splittings of t2^32E and t2^34A2 of SrTiO3:Cr^3+ have been calculated.The important results of Yc.Zc,Pc and Qc have also been evaluated.It is the admixtures of basic wavefunctions resulted from the spin-orbit interaction and /or Coulomb interaction and /or Kramers degeneracy that make the strain-induced splittings of the levels nonzero.It is found that there are nonvanishing matrix elements of operators T2ξ between wavefuncgtions with positive Ms and those with negative Ms′ and those with negative ms′,which have important effects on the strain-induced splittings of the levels.展开更多
A three-layer structure back-propagation network model based on the non-linear relationship between the purity of the perovskite-type SrTiO3 nano-crystal samples and the technology factors, such as reaction time, reac...A three-layer structure back-propagation network model based on the non-linear relationship between the purity of the perovskite-type SrTiO3 nano-crystal samples and the technology factors, such as reaction time, reaction temperature, raw material adding amount of NaOH and SrCl2, and the rate of TiCl4/Hl, was established. The input variables were pretreated by using the main component analysis firstly. Moreover, the momentum terms were introduced so as to accelerate the converging rate and avoid the non-converging situation. At the same time, the variable learning speed was adopted. The results show that the improved back propagation neural network model is very efficient for the prediction of the perovskite-type SrTiO3 nano-crystal sample purity.展开更多
文摘By using the superposition model,the tetragonal field parameters Ds and Dt are calculated from the structural data of（TiO6）9- cluster in SrTiO3 crystal.Based on these values,the EPR g factors of the rhombic Ti3+ center in SrTiO3 are calculated by use of only one adjustable parameter.The results show good agreement with the observed values.
文摘为制备具有电容和压敏特性的 Sr Ti O3双功能器件 ,以 Sr(NO3) 2 ,Ti(OC4 H9) 4为原料 ,用溶胶 -凝胶方法制备 Sr Ti O3材料 ,研究了水和醋酸等对 Sr Ti O3材料的影响机理 ,并对其进行 X-射线衍射、红外光谱和 TEM分析 ,证明该薄膜为纳米晶体结构 ,晶粒尺寸为 1 2～ 2 5nm。
文摘By using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix at normal and various pressures,the g factor of the ground state of SrTiO3:Cr^3+ and its pressure-induced shift have been microscopically calculated.Only by taking the local strains around Cr^3+ in SrTiO3:Cr^3+(which are about twice the bulk ones)and corresponding P-χ dependence,can we obtain a good agreement etween the calculated result of pressure-induced shift of ground-state g factor and the experimental one.The physical origins of this pressure-induced shift have been explained.It is found that the change of Dq^-1 with pressure makes main contribution to the pressure-induced shift of ground-state g factor of SrTiO3:Cr^3+.By using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix at normal pressure,the relevant matrix elements and accordingly strain-induced splittings of t2^32E and t2^34A2 of SrTiO3:Cr^3+ have been calculated.The important results of Yc.Zc,Pc and Qc have also been evaluated.It is the admixtures of basic wavefunctions resulted from the spin-orbit interaction and /or Coulomb interaction and /or Kramers degeneracy that make the strain-induced splittings of the levels nonzero.It is found that there are nonvanishing matrix elements of operators T2ξ between wavefuncgtions with positive Ms and those with negative Ms′ and those with negative ms′,which have important effects on the strain-induced splittings of the levels.
基金Project (2004E113) Supported by the Natural Science Basic Research Plan of Shaanxi Province of China
文摘A three-layer structure back-propagation network model based on the non-linear relationship between the purity of the perovskite-type SrTiO3 nano-crystal samples and the technology factors, such as reaction time, reaction temperature, raw material adding amount of NaOH and SrCl2, and the rate of TiCl4/Hl, was established. The input variables were pretreated by using the main component analysis firstly. Moreover, the momentum terms were introduced so as to accelerate the converging rate and avoid the non-converging situation. At the same time, the variable learning speed was adopted. The results show that the improved back propagation neural network model is very efficient for the prediction of the perovskite-type SrTiO3 nano-crystal sample purity.
