EPR and Optical Absorption Studies of Mn(superscript 2+) Doped Diglycine Calcium Chloride Tetrahydrate

Ram Kripal；Manisha Bajpai

Chinese Journal of Physics

48卷5期（2010 / 10 / 01）

671 - 682

英文

Electron paramagnetc resonance (EPR) studies of Mn(superscript 2+) doped diglycine calcium chloride tetrahydrate were carried out at liquid nitrogen temperature. The values of the spin Hamiltonian parameters that give a good fit to the observed EPR spectra were obtained. The values of the spectroscopic splitting factor (g), hyperfine structure constants (A and B), axial zero field splitting parameter (D), rhombic zero field splitting parameter (E), and cubic field splitting parameter (a) are: g=1.9709 ± 0.0002, A=(106 ± 2) × 10^(-4) cm^(-1), B=(93 ± 2) × 10^(-4) cm^(-1), D=(276 ± 2) × 10^(-4) cm^(-1), E=(58 ± 2) × 10^(-4) cm^(-1), and a=(20 ± 1) × 10^(-4) cm^(-1) for Site I and g=1.9756 ± 0.0002, A=(107 ± 2) × 10^(-4) cm^(-1), B=(93 ± 2) × 10^(-4) cm^(-1), D=(275 ± 2) × 10^(-4) cm^(-1), E=(59 ± 2) × 10^(-4) cm^(-1), and a=(22 ± 1) × 10^(-4) cm^(-1) for Site II. The percentage of covalency of the metal-ligand bond has also been determined. The optical absorption study was performed at room temperature. The observed optical bands are assigned as transitions from the 6A1g(S) ground state to various excited quartet levels of a Mn(superscript 2+) ion in a cubic crystalline field. The electron repulsion parameters (B and C) and crystal field splitting parameter (Dq) were obtained as: B=770 cm^(-1), C=2322 cm^(-1), and Dq=716 cm^(-1).