Accession Number : AD0707749

Title :   LOW-TEMPERATURE THERMAL CONDUCTIVITY MEASUREMENTS IN SEMICONDUCTORS.

Descriptive Note : Final rept. 1 Jul 59-31 May 68,

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

Personal Author(s) : Redin,R. Daniel

Report Date : 15 JUN 1970

Pagination or Media Count : 28

Abstract : Thermal conductivity measurements have been made at low temperatures on a heavily doped p-type sample of InSb and on the magnetic semiconductors EuO and EuS in the vicinity of their Curie temperatures. Further evidence of an anomaly in the thermal conductivity of EuO in the vicinity of its Curie temperature of 69 K was obtained but during the course of continuing measurements the anomaly disappeared. The cause of the change in behavior is believed due to a breakdown, on a microscopic scale, of the pressed-powder sample. The thermal conductivity of a pressed-powder EuS sample showed a predominantly T squared temperature dependence over the temperature range 13.5 K to 17.6 K. There was no evidence of any anomalous behavior near the Curie temperature of 16.4 K. Extension of thermal conductivity measurements down to 17 K now has made available thermal conductivity values from 17 K to 640 K for a polycrystalline sample of InSb containing 10 to the 20th power acceptors per cc. A theoretical analysis of the results indicates that throughout this temperature range the thermal conductivity is due primarily to high-frequency transverse acoustic phonons with a small contribution due to high-frequency longitudinal phonons. The conductivity due to low-frequency transverse and longitudinal phonons is negligible due to strong scattering by holes. (Author)

Descriptors :   (*SEMICONDUCTORS, *THERMAL CONDUCTIVITY), (*INDIUM ANTIMONIDES, THERMAL CONDUCTIVITY), (*EUROPIUM COMPOUNDS, THERMAL CONDUCTIVITY), OXIDES, SULFIDES, ANOMALIES, CRYOGENICS, PHONONS

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE