OPTICAL AND MAGNETIC RESONANCE STUDY OF TRANSITION METAL MIXED CRYSTALS.
Final rept. 1 Jul 66-30 Jun 69,
SOUTH CAROLINA UNIV COLUMBIA DEPT OF PHYSICS
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The report covers research carried out on several mixed-crystal systems. 1 Manganese spinels were studied over the entire concentration range of Mg,MnAl2O4. The electron spin resonance ESR spectrum arising from isolated Mn2 ions at low concentration was characterized by a narrow -12 arrow 12 sextet and four other broader overlapping fine structure sextets. 2 The Anderson model for exchange narrowing was solved for spins I 1, 32, 2, 52 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 Cu2 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 Tuttons salts was calculated for the minimum energy state.
- Solid State Physics