EPR and optical absorption studies of Cr 3+ ions in d-gluconic acid monohydrate

Abstract

EPR studies are carried out on Cr 3+ ions doped in d-gluconic acid monohydrate (C 6H 12O 7·H 2O) single crystals at 77 K. From the observed EPR spectra, the spin Hamiltonian parameters g, | D| and | E| are measured to be 1.9919, 349 (×10 −4) cm −1 and 113 (×10 −4) cm −1, respectively. The optical absorption of the crystal is also studied at room temperature. From the observed band positions, the cubic crystal field splitting parameter Dq (2052 cm −1) and the Racah interelectronic repulsion parameter B (653 cm −1) are evaluated. From the correlation of EPR and optical data the nature of bonding of Cr 3+ ion with its ligands is discussed.