Effect Of Charge Transfer Mechanism To The High Valence Vanadium Ion Crystal Of The EPR Parameters

3d1 ions are important transition metal ions,for example,the crystals doped with V4+ ions are a kind of crystals with laser and nonlinear optical properties,so it is very meaningful to study the properties of doped materials.Previous studies found that the properties of doped materials are closely related to the defect structure of impurity centers,and that spectral and electron paramagnetic resonance(EPR)spectra have sensitive dependence on impurity defect distortion,therefore,through the study of the spectral and EPR spectra,the relationship between the optical and magnetic properties of the impurity ions in the crystal and the defects can be obtained.In recent years,the crystal field(CF)mechanism is mainly considered,and based on the molecular orbital theory and the spin-Hamiltonian theory,the treatment of EPR parameters and spectral properties of doped metal ions have made great progress.In this thesis,the valence state of doped with V4+ ions are relatively high,and the charge transfer(CT)transition energy is relatively low,we need to consider the quantitative contribution of the CT mechanism to EPR parameters.The innovations of this thesis are as follows:(1)This thesis breaks through the limitation of CF mechanism,we considered the contribution of CT mechanism to EPR parameters,and deduced the high-order perturbation formulas of the 3d1 ions.We further improved the theoretical formulas,and the quantitative relationship of the corresponding parameters were also obtained.(2)According to the theoretical formula,the g factors and hyperfine structure constants A of(10)×224SOVO:OH3KZn Cl crystals doped with V4+ions were explained,and the information of the V4+central defect structure was obtained.(3)After analysis of the optical spectral data,the EPR parameters of the V4+impurity centers in × 2(10)24POVO:OH6Zn K crystals were obtained in thehexa-coordinate octahedron,and the theoretical results were in agreement with the experimental results,and found that the contribution of the CT mechanism to the g factors and A values are of the same order of magnitude as that of the third order perturbation term of the CF mechanism.(4)The analysis of the data demonstrated that the influence of CT on EPR parameters cannot be ignored,in theory,it was instructive to understand the g factors and A values.