Accession Number : AD0698840

Title :   OPTICAL AND MAGNETIC RESONANCE STUDY OF TRANSITION METAL MIXED CRYSTALS.

Descriptive Note : Final rept. 1 Jul 66-30 Jun 69,

Corporate Author : SOUTH CAROLINA UNIV COLUMBIA DEPT OF PHYSICS

Personal Author(s) : Poole,Charles P. , Jr

Report Date : 01 OCT 1969

Pagination or Media Count : 71

Abstract : The report covers research carried out on several mixed-crystal systems. (1) Manganese spinels were studied over the entire concentration range of (Mg,Mn)Al2O4. The electron spin resonance (ESR) spectrum arising from isolated Mn+2 ions at low concentration was characterized by a narrow -1/2 (arrow) 1/2 sextet and four other broader overlapping fine structure sextets. (2) The Anderson model for exchange narrowing was solved for spins I = 1, 3/2, 2, 5/2 and the results employed to explain the spinel data. (3) Single crystals of chromia alumina were studied at about 50 and about 75 mole per cent chromia. The former exhibited typical ruby D-term anisotropies, while for the latter sample an isotropic spectrum arose from exchange narrowing. (4) An optical and ESR study of Cu+2 in turquoise was carried out and correlated with crystal field theory calculations. (5) A systematic treatment for the calculation of crystal field potentials was cormulated, and a number of practical formulae for commonly occurring symmetry environments were calculated. (6) Mossbauer double resonance with the simultaneous application of optical, NMR and ESR signals was analyzed, and a prediction was made of the expected spectra. (7) The spin orientation in copper Tutton's salts was calculated for the minimum energy state.

Descriptors :   (*SOLID SOLUTIONS, ELECTRON PARAMAGNETIC RESONANCE), BAND THEORY OF SOLIDS, MOSSBAUER EFFECT, SINGLE CRYSTALS, ALUMINA, SPINEL, OXIDES, CHROMIUM COMPOUNDS, SEMICONDUCTORS, LASERS, MASERS, CRYOGENICS

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE