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

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.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1963
Accession Number
AD0482322

Entities

People

  • Charles H. Stilwell Jr.
  • Robert W. Oliver

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Propagation
  • Acoustic Waves
  • Elastic Waves
  • Frequency
  • Internal Friction
  • Magnetic Fields
  • Measurement
  • Mechanical Properties
  • Metals
  • Neel Temperature
  • Polarization
  • Pressure Measurement
  • Resistance
  • Resistance Thermometers
  • Secondary Waves
  • Vapor Pressure

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Spectroscopy.
  • Superconducting Magnet Technology