ULTRASONIC MEASUREMENTS IN MANGANESE FLUORIDE IN THE REGION OF THE NEEL TEMPERATURE

reportActive / Technical Report | Accession Number: AD0482322 | Open PDF

Abstract:

Ultrasonic wave velocities were measured in MnF2 in the region of the antiferromagnetic transition. Both longitudinal and shear waves were propagated in the 110 direction at frequencies up to 65 mc. The longitudinal waves showed an attenuation peak at the Neel temperature which increased with frequency. A magnetic field of 3.6 kilogauss narrowed the attenuation peak slightly, but had no affect on the amount of attenuation, the location of the peak, nor on the velocity. Shear waves exhibited a gradual increase in attenuation with decreasing temperature, but had no attenuation peak. A magnetic field of 5.5 kilogauss increased the attenuation of the shear waves very slightly. Although it was not possible to determine a complete set of moduli, the values at 70 K. appropriate to the waves measured are given.

Author(s):
Oliver, Robert W. ; Stilwell, Jr, Charles H.
Author Organization(s):
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
Descriptive Note:
Master's thesis
Pagination:
0025

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Monitor Series:
NPS
 Subject Terms
Joint Capability Areas:
JCA_1_Force Support; JCA_1.2.7_Experimentation; JCA_1.3_Human Capital Management; JCA_6.1.1_Wired Transmission; JCA_6_Net Centric; JCA_1.3.2_Personnel Management
Modernization Areas:
Directed Energy
Communities of Interest:
Advanced Electronics
Descriptor(s):
*ANTIFERROMAGNETISM, *FERROMAGNETIC MATERIALS, *FLUORIDES, *MANGANESE COMPOUNDS, ATTENUATION, CRYOGENICS, MAGNETIC FIELDS, MAGNETIC PROPERTIES, MECHANICAL PROPERTIES, PHASE STUDIES, SINGLE CRYSTALS, THERMODYNAMICS, ULTRASONIC RADIATION, WAVE PROPAGATION
Field(s)/Group(s):
Crystallography, Electricity and Magnetism
Keyword(s):
MANGANESE FLUORIDE, NEEL TEMPERATURE
Report Date:
1963 Jan 01