Accession Number : AD0271744

Title :   SPIN-LATTICE RELAXATION IN DYSPROSIUM ETHYL SULPHATE

Corporate Author : OXFORD UNIV (ENGLAND) CLARENDON LAB

Personal Author(s) : COOKE,A.H. ; FINN,C.B.P.

Report Date : JUL 1961

Pagination or Media Count : 1

Abstract : Measurements of spin-lattice relaxation in dysprosium ethyl sulphate using magnetic fields along the symmetry axis of the crystal have shown that at temperatures in the helium range the predominant relaxation mechanism is the resonance relaxation process, in which the relaxation time T1 varies exponentially with 1/T. Application of crystalline field theory shows that in this substance the direct one-phonon process may be expected to be important at low temperatures, but that the relaxation time for this process will depend strongly on the angle between the magnetic field and the crystal axis, and should be least when the angle is pi/4. This was confirmed experimentally. When the magnetic field is applied at pi/4 to the axis the variation of the relaxation time with temperature and with field is quite changed, and at high fields it is possible to follow the transition from the resonance to the direct relaxation process, in which the relaxation time is inversely proportional to the temperature. (Author)

Descriptors :   *DYSPROSIUM, *ETHYL RADICALS, *NUCLEAR SPINS, *RELAXATION TIME, *SULFATES, CRYSTAL LATTICES, MAGNETIC FIELDS, PHONONS, RESONANCE, SINGLE CRYSTALS, TEMPERATURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE