Accession Number : AD0672773

Title :   THERMAL CONDUCTIVITY AND ELECTRICAL RESISTIVITY MEASUREMENTS OF EUO ACROSS THE CURIE TEMPERATURE IN A MAGNETIC FIELD.

Descriptive Note : Technical rept.,

Corporate Author : SOUTH DAKOTA SCHOOL OF MINES AND TECHNOLOGY RAPID CITY DEPT OF PHYSICS

Personal Author(s) : Konantz,Mark L.

Report Date : 01 JUL 1968

Pagination or Media Count : 65

Abstract : The thermal conductivity K of a hot-pressed sample of EuO (90% EuO, 10% Eu2O3) was measured in the temperature range 60-300K using the linear absolute method. K falls off sharply as the temperature goes below 90K, and then rises again by 60K. The dip is not symmetric but its sides intersect at 69K. K was also measured in a longitudinal magnetic field of 100 gauss in the temperature range 60-78K. A dip at 69K was again observed; however, in the magnetic field K fell off less sharply and the dip was much shallower. The electrical resistivity r was also measured. In the absence of the magnetic field r deviated by less than 1% from a value of 0.040 ohm-cm over the entire temperature range 60-300K. Application of the magnetic field resulted in changes of r of less than 2% throughout this same temperature range. The downward dip in the thermal conductivity at the ferromagnetic-paramagnetic transition temperature of 69K can be qualitatively understood in terms of critical scattering of phonons by critical fluctuation in the energy density of the spin system. (Author)

Descriptors :   (*FERROMAGNETIC MATERIALS, RARE EARTH ELEMENTS), (*RARE EARTH ELEMENTS, TRANSPORT PROPERTIES), (*EUROPIUM COMPOUNDS, TRANSPORT PROPERTIES), THERMAL CONDUCTIVITY, ELECTRICAL RESISTANCE, MAGNETIC FIELDS, PHASE STUDIES, TRANSITION TEMPERATURE, CRYOGENICS, NUCLEAR SPINS, PHONONS, INTERACTIONS, THESES

Subject Categories : Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE