Comparative analysis of energy-level splitting of Pr^(3+) doped in LiYF_4 and LiBiF_4 crystals:a complete energy matrix calculation

Based on the combination of Racah＇s group-theoretical consideration with Slater＇s wavefunction, a 91 ×91 complete energy matrix is established in tetragonal ligand field D2d for Pr3＋ ion. Thus, the Stark energy-levels of Pr3＋ ions doped separately in LiYF4 and LiBiF4 crystals are calculated, and our calculations imply that the complete energy matrix method can be used as an effective tool to calculate the energy-levels of the systems doped by rare earth ions. Besides, the influence of Pr3＋ on energy-level splitting is investigated, and the similarities and the differences between the two doped crystals are demonstrated in detail by comparing their several pairs of curves and crystal field strength quantities. We see that the energy splitting patterns are similar and the crystal field interaction of LiYF4：Pr3＋ is stronger than that of LiBiF4：Pr3＋.

Theoretical Investigations of the Local Structure Distortion and EPR Parameter for Ni2＋-doped Perovskite Fluorides

By analyzing the optical spectra and electron paramagnetic resonance parameter D, the local structure distortion of （NiF6）4- clusters in AMF3 （A=K, Rb; M=Zn, Cd, Ca） and K2ZnF4 series are studied using the complete energy matrix based on the double spin-orbit coupling parameter model for configuration ions in a tetragonal ligand field. The results indicate that the contribution of ligand to spin-orbit coupling interaction should be considered for our studied systems. Moreover, the relationships between D and the spin-obit coupling coefficients as well as the average parameter and the divergent parameter are discussed.

Investigations of the electron paramagnetic resonance parameters and the tetragonal local structure for (VCl_6)^(4-) coordination complex in MCl:V^(2+) (M=Na,K,Rb) systems

By simulating the electron paramagnetic resonance （EPR） and optical spectra on the basis of the 120 × 120 complete energy matrix, this paper determines the local lattice structure parameters R1 and R2 for MCl：V2＋ （M=Na, K, Rb） systems at 77K, 195 K and RT （room temperature 295 K or 302 K）, respectively. The theoretical results indicate that there exists a compressed distortion in MCl：V2＋ systems. Meanwhile, it finds that the structure parameters R1, R2 and ｜△R｜（ = R1 - R2） increase with the rising temperature. Subsequently, from the analysis it concludes that the relation of EPR parameter D vs. △R is approximately linear. Finally, the effects of orbital reduction factor k on the g factors for the three systems have been discussed.

Theoretical investigations of the local distortion and electron paramagnetic resonance parameter for CdCl_2:V^(2+) and CsMgX_3:V_^(2+)(X=Cl,Br) systems

This paper systematically investigates the local distortion and electron paramagnetic resonance （EPR） parameter for CdCl2：V^2＋ and CsMgX3：V^2＋ （X=Cl, Br） systems on the basis of the complete energy matrix, in which not only the contributions due to the spin-orbit coupling of the central ions but also that of the ligands are considered. To describe the difference of overlapping between d-orbits and p orbit, two spin-orbit coupling coefficients are introduced. By simulating the crystal field parameter and EPR parameter, the local distortion parameters are studied and the relationships between the EPR parameter and the spin-orbit coupling coefficients as well as divergent parameter are discussed. These results show that the local structures exhibit compression distortion for CdCl2：V^2＋ and elongation distortions for CsMgX3：V^2＋ （X：Cl, Br）, respectively. It notes that the empirical formula R≈RH T （ri - rh）/2 is not suitable for CdCl2：V^2＋ and CsMgX3：V^2＋ （X=Cl, Br） systems. The contributions of ligand to spin-orbit coupling interaction cannot be neglected for strong covalent systems, especially for V^2＋ doped in CsMgBr3：V^2＋.

Optical and magnetic properties of transition-metal ions in tetrahedral and octahedral compounds

This paper presents the complete energy matrix of the 3d2system containing the electron-electron interaction, the ligand-fieldinteraction, the spin-orbit coupling interaction, and the Zeeman interaction, in which the optical spectra and g-factor of V3+andTi2+ions in the series of tetrahedral AIIBVI(AII=Zn, Cd, BVI=S, Se, Te) semiconductor materials are determined. In the inves-tigation of the optical and magnetic properties of these transition-metal ions in the tetrahedral coordination complexes, wecompared the data obtained from the transition-metal ions in the tetrahedral coordination complexes with those obtained fromthe corresponding ions in the octahedral ones, and found that the tetrahedral complexes have weaker crystal-field strength, in-verse energy level ordering and stronger covalence effect.