Crystalline Electric Field Scheme of CeRh_2 Ga

The crystalline electric field (CEF) scheme of rare earth compound CeRh_2Ga was obtained by means of fitting the temperature dependence of inverse magnetic susceptibility. The CEF analysis shows that this compound has a doublet ground state. The first and second excited CEF doublet levels are estimated to be about 56 and 937 K, respectively. The calculated results are in good agreement with experimental data.

Exchange and Crystalline Electric Field Interactions in Tm_2Fe_(14)B Compound

A series of magnetic properties of Tm_2Fe_(14)B are explained quantitatively by the calculations based on the single ion model. The magnetic properties include the temperature dependence of the spontaneous magnetization, the spin reorientation temperature and the magnetization curves along the principal crystal axes at 4.2, 100, 150 and 200 K. The values of the exchange field and the crystalline electric field parameters used in the calculations are μ_BH_(ex)(T=0 K)=135, B_2~0=1.77, B_2~2=±2.97, B_4~0=-3.06×10^(-3), B_4^(-2)=0, B_4~4=-6.82×10^(-3), B_6~0=1.05× 10^(-5), B_6^(-2)=±7.40×10^(-5), B_6~4=1.96×10^(-4), and B_6^(-6)=0 all in K unit. The magnetization processes of the Fe-and Tm-sublattices at different temperatures are analysed. The processes are characterized by the non-collinearity between the magnetic moments of the Fe-and Tm-sublattices.

Non-Kramers doublet ground state in a quaternary cubic compound PrRu_(2)In_(2)Zn_(18) investigated by ultrasonic measurements

We performed ultrasonic measurements on a quaternary cubic compound PrRu_(2)In_(2)Zn_(18) to explore the ground state properties derived from non-Kramers Γ_(3) doublet of Pr^(3+).PrRu_(2)In_(2)Zn_(18) is a quaternary derivative of the ternary compound PrRu_(2)Zn_(20) that exhibits a structural phase transition at T_S=138 K.In PrRu_(2)In_(2)Zn_(18),the Zn atoms at the 16c site in PrRu_(2)Zn_(20) are selectively replaced by In atoms.A monotonic increase was observed in the temperature dependence of elastic constants C_L=(C_(11)+2C_(12)+4C_(44))/3 and C_T=(C_(11)-C_(12)+C_(44))/3 in the temperature range around T_S to which an elastic softening was observed in(C_(11)-C_(12))/2 for PrRu_(2)Zn_(20).The disappearance of the softening indicates that the structural transition in PrRu_(2)Zn_(20) is suppressed by the substitution of Zn ions by In ones with a larger ionic radius.Alternatively,the C_T of PrRu_(2)In_(2)Zn_(18) exhibits a precursor Curie-type elastic softening toward low temperatures being responsible for the non-Kramers Γ_(3) ground state.We discuss the ground state and the evolution of the elastic properties of the different single-crystal samples of PrRu_(2)In_(2)Zn_(18) grown under different conditions.

Crystal Growth,Structure,and Spectral Properties of Cr^(4+):Ca_(2)(Al_(1.8)Ga_(0.2))SiO_(7)

A new crystal,Ca_(2)(Al_(1.8)Ga_(0.2))SiO_(7),was obtained by substituting Ga^(3+)ions for some Al^(3+)ions in Ca_(2)Al_(2)SiO_(7)crystal.The growth,structure and optical spectroscopic properties of Cr^(4+)-doped Ca_(2)(Al_(1.8)Ga_(0.2))SiO_(7)were studied.It shows strong absorption at 693 and 762 nm and a broad emission band with peak wavelength at 1223 nm.Both the absorption and emission peaks of Cr^(4+)-doped Ca_(2)(Al_(1.8)Ga_(0.2))SiO_(7)crystal are red-shifted in comparison with that of Cr^(4+)-doped Ca_(2)Al_(2)SiO_(7)crystal due to its weaker lattice field.The investigation results show that there is only one kind of tetrahedral site for Cr^(4+)occupation in the lattice of Ca_(2)(Al_(1.8)Ga_(0.2))SiO_(7)crystal.