Accession Number : AD0757884

Title :   EPR in Solids.

Descriptive Note : Final rept. 1 Apr 71-31 Mar 72,

Corporate Author : MASSACHUSETTS UNIV BOSTON

Personal Author(s) : Shane,John R.

Report Date : SEP 1972

Pagination or Media Count : 40

Abstract : A description of the EPR spectrum of Cr(3+) in Li2Ge7O15 is presented. At room temperature there are four equally populated sites which differ only in the orientation of their principal axes with respect to the orthorhombic unit cell. The locations of the principal axes and the spin-Hamiltonian parameters have been determined. At low temperatures there are two sets of four equivalent sites which are no longer related by operators of the group D(2h). Evidence of a crystallographic phase transition near 0C has been determined from the temperature dependence of the resonance. Conclusions regarding the Cr(3+) site occupancy are presented. A procedure for determining analytically the orientations of principal axes of equivalent sites has been developed. The formulation and application of this method are described. The dominant spectrum observed in unswept quartz crystals has been identified. (Author)

Descriptors :   (*PARAMAGNETIC RESONANCE, *CRYSTAL DEFECTS), IMPURITIES, QUARTZ, CHROMIUM, IRON, GERMANIUM COMPOUNDS, SALTS, CRYSTAL STRUCTURE, NUMERICAL ANALYSIS, DOPING

Subject Categories : Physical Chemistry
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE