Effect of Heat Treatment on Acoustic Properties of Chromium Polycrystals at Low Temperatures |
| Journal |
Solid State Phenomena (Volume 137) |
| Volume |
Interaction between Defects and Anelastic Phenomena in Solids |
| Edited by |
Igor S. Golovin and Daniil M. Levin |
| Pages |
43-48 |
| DOI |
10.4028/www.scientific.net/SSP.137.43 |
| Online since |
March, 2008 |
| Authors |
P.P. Pal-Val,
L.N. Pal-Val,
S.B. Golovina,
Igor S. Golovin
|
| Keywords |
Antiferromagnetism, Chromium, Elastic Moduli, Internal Friction, Low Temperature, Magnetic Phase Transition, Néel Point, Spin Density Wave, Spin-Flip Transition |
| Abstract |
Acoustic properties of polycrystalline Cr samples of 99.99 % purity are investigated at
frequencies of longitudinal vibrations f ~ 75 kHz and of bending vibrations at 0.6 < f < 1.5 kHz
when thermocycling within the temperature interval 5 − 330 K. Special attention is paid to the
acoustic anomalies in the vicinity of the magnetic phase transitions: the Néel point and the spin-flip
transition. In the as-received samples, a significant hysteresis of the acoustic properties has been
found for the first time. The effect of heat treatments on internal friction and elastic properties of
chromium polycrystals is also investigated. The data obtained are compared with the effect of small
preliminary deformation and а long-time ageing at room temperature on the ultrasound anomalies in
Cr single crystal. The observed behavior of the acoustic properties may be caused by changes in the
antiferromagnetic domain structure in Cr polycrystals under the action of thermoelastic stresses
arising from quenching, preliminary plastic deformation or thermocycling. |
| Full Paper |
Get the full paper by clicking here
|
| Preview |
Free first page example |
