An electron spin resonance study of Mn²⁺doped calcium hydrazine carboxylate monohydrate

Abstract

Single crystals of calcium hydrazine carboxylate, monohydrate have been studied by ESR of Mn²⁺ doped in the calcium sites. X-band ESR indicated a large crystal field splitting necessitating experiments at Q band. The analysis shows two magnetically inequivalent (but chemically equivalent) sites with g _xx = 2.0042±0.0038,g _yy=2.0076 ±0.0029,g _zz=2.0314±0.001,A _zz=0.0099±0.0002 cm^-1,A _xx=0.0092±0.0002 cm^-1,A _yy=0.0082±0.0002 cm^-1,D=3/2D_zz=0.0558±0.0006 cm^-1, and E=1/2 (D_yy-D_yy)=0.0127±0.0002 cm^-1. One of the principal components of the crystal field, (D_zz), is found to be along the Ca ↔Ca direction in the structure and a second one, (D_xx), along the perpendicular to the plane of the triangle formed by three neighbouring calciums. The A tensor is found to have an orientation different from that of the g and D tensors reflecting the low symmetry of the Ca²⁺ sites.