Accession Number : AD0695494

Title :   ULTRASONIC MEASUREMENTS IN MnF2 NEAR THE NEEL TEMPERATURE,

Corporate Author : BOEING SCIENTIFIC RESEARCH LABS SEATTLE WASH

Personal Author(s) : Leisure,R. G. ; Moss,R. W.

Report Date : AUG 1969

Pagination or Media Count : 26

Abstract : The ultrasonic velocity has been measured for both longitudinal and transverse waves in the (110) and (001) directions in MnF2 near the critical point. A sharp minimum was observed for longitudinal waves. This minimum coincided with an attenuation maximum and occurred at the Neel temperature. The velocity anomaly was frequency independent for the two frequencies used. No effect was observed for transverse waves. The attenuation was measured over a wide temperature range. The temperature dependence of both critical attenuation and velocity is given by (T-T sub N) to -0.33 power for T greater than T sub N, where T sub N is the Neel temperature of 67.34K. (Author)

Descriptors :   (*MAGNETIC MATERIALS, PHASE STUDIES), (*MANGANESE COMPOUNDS, *ULTRASONIC RADIATION), FLUORIDES, ULTRASONIC PROPERTIES, ATTENUATION, PROPAGATION, TRANSITION TEMPERATURE, ANOMALIES, ANTIFERROMAGNETISM, MAGNETIC PROPERTIES, POLARIZATION, TEST METHODS, EXPERIMENTAL DATA

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE