Accession Number : AD0707712

Title :   ELECTRON-PARAMAGNON INTERACTION EFFECTS IN NEARLY FERROMAGNETIC METALS.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Schindler,A. I.

Report Date : 21 MAY 1970

Pagination or Media Count : 27

Abstract : The effects of itinerant spin-sensity fluctuations, or paramagnons, on various physical properties including the electronic specific heat coefficient gamma, the low temperature electrical and thermal resistivities, and the ideal Lorenz number were reviewed. Paramagnon interaction effects, which are important in determining the low-temperature properties of strongly-exchange-enhanced paramagnetic metals like palladium, can be strongly modified by alloying additions, in particular nickel. The exchange enhancement increases with nickel content until, at some critical composition, the system goes ferromagnetic. Two models have been introduced to explain the properties of such alloys. In the one model, the uniform enhancement model, it is assumed that the effect of alloying with nickel may be represented by an increase in the exchange enhancement of the matrix. In the other model, the local enhancement model, the alloy is treated in a scheme valid in the dilute limit, where the spatial inhomogeneities of the spin density fluctuations in the vicinity of the nickel site are taken into account. Both of these models were examined and compared with experimental observations of Pd, Pt, and Rh with alloying additions of Ni. The theoretical calculations of various composition-dependent and temperature-dependent effects gave, in almost all cases, reasonable, but somewhat large, estimates for their magnitudes. (Author)

Descriptors :   (*PARAMAGNETIC MATERIALS, MAGNETIC PROPERTIES), PALLADIUM ALLOYS, PLATINUM ALLOYS, RHODIUM ALLOYS, THERMAL CONDUCTIVITY, ELECTRICAL RESISTANCE, SPECIFIC HEAT, NICKEL, IMPURITIES

Subject Categories : Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE