Accession Number : AD0778705

Title :   Magnetic Field Dependence of Nuclear Relaxation in Antiferromagnets.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF PHYSICS

Personal Author(s) : Freyne,F.

Report Date : SEP 1973

Pagination or Media Count : 51

Abstract : The contributions of higher order scattering processes, in particular three magnon processes, to the nuclear spin lattice relaxation rate of F19 and Mn55 nuclei in antiferromagnetic MnF2 are examined. It is shown that this three magnon rate, aided by an exchange enhanced process, has a significant magnetic field dependence, for fields along the magnetic easy axis, as the spin flop transition is approached. The three magnon relaxation rate becomes comparable in magnitude to the two magnon rate in this magnetic field region. Theoretical curves are presented for the predicted three magnon spin lattice relaxation rate contribution in NMR experiments on MnF2. Other higher order processes are shown to yield smaller corrections to the relaxation rate as compared to this three magnon rate. (Author)

Descriptors :   *Antiferromagnetism, *Magnons, *Nuclear magnetic resonance, Manganese compounds, Fluorides, Magnetic fields, Light scattering, Raman spectra

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE