Accession Number : AD0263805

Title :   THEORY OF SPIN WAVE INTERACTIONS IN FERROMAGNETISM

Corporate Author : MARYLAND UNIV COLLEGE PARK

Report Date : JUL 1961

Pagination or Media Count : 1

Abstract : The interactions of spin waves in an ideal Heisenberg model of a ferromagnet are studied. In particular, the effect of spin wave interactions on the free energy and spontaneous magnetization are examined. Treating a spin wave as a local phenomena, only binary collisions between spin waves need be considered at low temperature. The free energy of the system is developed as an expansion in terms of a binary kernal function; this binary kernal function is determined from the two particle propagator, which can formally be evaluated. When the free energy expansion is evaluated, the results of Dyson are obtained. That is, the lowest order correction term introduced in the spontaneous magnetization by spin wave interactions is of order T(4). (Author)

Descriptors :   *FERROMAGNETISM, CRYOGENICS, MAGNETIC PROPERTIES, NUCLEAR SPINS, QUANTUM STATISTICS, SOLID STATE PHYSICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE