Accession Number : AD0430574

Title :   MAGNETIC RELAXATION IN RARE EARTH SALTS,

Corporate Author : OXFORD UNIV (ENGLAND) CLARENDON LAB

Personal Author(s) : Cooke,A. H. ; Daintree,E. J.

Report Date : 20 SEP 1963

Pagination or Media Count : 11

Abstract : Experiments have been made on spin-lattice relaxation in rare earth salts in the helium range of temperatures. It is found that at the lowest temperatures, at which relaxation by the 'direct' one-phonon process would be expected to predominate, the relaxation time derived from measurements by the Casimir-Du Pre low frequency method departs in several ways from the predictions of theory, and in particular increases with magnetic field. It is shown that these features can be accounted for if allowance is made for variations of the temperature of the phonons in contact with the spin system, due to a 'phonon bottleneck,' of the type postulated by Scott and Jeffries. (Author)

Descriptors :   (*RARE EARTH COMPOUNDS, MAGNETIC PROPERTIES), SPINNING(MOTION), HELIUM, TEMPERATURE, PHONONS, RELAXATION TIME, MEASUREMENT, LOW FREQUENCY, THEORY, MAGNETIC FIELDS, CRYSTAL LATTICES, ENERGY, IONS, ELECTRONS, SULFATES, ANISOTROPY

Distribution Statement : APPROVED FOR PUBLIC RELEASE