Effect of lattice defects in divalent lattices by incorporating trivalent ions in biominerals: An EPR study of Cr(III) in zinc(II) potassium phosphate hexahydrate by H. Anandalakshmi, R. Venkatesan, P. Sambasiva Rao

Crystal Research and Technology

Cryst. Res. Technol. 39, 78 (2004) - Abstract -

Effect of lattice defects in divalent lattices by incorporating trivalent ions in biominerals: An EPR study of Cr(III) in zinc(II) potassium phosphate hexahydrate

H. Anandalakshmi, R. Venkatesan, P. Sambasiva Rao

Department of Chemistry, Pondicherry University, R.V. Nagar, Kalapet, Pondicherry- 605 014, India

Keywords	charge compensating vacancy, divalent and trivalent ions, D-tensors, single crystal, lattice defect
PACS	61.72Hh, 76.30Fc
DOI	10.1002/crat.200310152

In order to understand the effect of charge compensating vacancies on the number, orientation and magnitude of D-tensors, single crystal EPR measurements have been carried out with Cr(III) in zinc(II) potassium phosphate hexahydrate at room temperature. During crystal rotations, a maximum of 6/7 resonance lines or a minimum of 2 is noticed. Crystal rotations done in the three orthogonal planes have yielded spin Hamiltonian parameters for one site with: g_xx=1.969, g_yy= 1.995, g_zz= 2.107; D_xx= 66.2 mT; D_yy= 91.7 mT, and D_zz=-157.9 mT. The powder EPR spectrum indicates a very broad line at g = 8, without any extra resonances from 0 to 650 mT both at room temperature and 77 K. The reason may be that due to large zero field splitting, the resonance at g = 2 is shifted to g = 8 position and the other resonances are below 0 or above 650 mT.

The full text of this paper in pdf-Format:

If you have come directly to this page, click this symbol

to go to the CRT homepage.