Rotational invariance and magnetoelastic phenomena in paramagnets

Journal Article · Tue Mar 01 04:00:00 EST 1977 · Phys. Rev., B; (United States)

DOI:https://doi.org/10.1103/PhysRevB.15.2718· OSTI ID:7306109

Wang, P S; Luethi, B

We measured sound-velocity changes for various geometries in the model paramagnet TmSb and in high magnetic fields. By measuring the c/sub 44/ mode with propagation direction k parallel and perpendicular to the magnetic field one finds a field-dependent splitting between the two modes, which should be absent in noninvariant magnetoelastic theory. This is evidence for the presence of rotationally invariant magnetoelastic interactions. A recently developed theory by Dohm and Fulde is used to quantitatively account for this effect. All relevant material parameters are known for TmSb and we can therefore make for the first time a test for this theory without adjustable parameters. The result is a surprisingly good agreement between experiment and theory. The inclusion of other higher-order magnetoelastic terms is discussed. A similar effect is observed for the c/sub 11/-c/sub 12/ mode, where we can account for the mode splitting with opposite sign to the c/sub 44/ case and where we can account for the order of magnitude of the effect with a simplified calculation. We also present analogous experimental results for paramagnetic Pr/sub 3/Te/sub 4/ in smaller fields, which we do not interpret quantitatively due to lack of knowledge of crystal electric field parameters for Pr/sup 3 +/.

• Research Organization: Physics Department, Rutgers University, New Brunswick, New Jersey 08903
• OSTI ID: 7306109
• Journal Information: Phys. Rev., B; (United States), Journal Name: Phys. Rev., B; (United States) Vol. 15:5; ISSN PLRBA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360104* -- Metals & Alloys-- Physical Properties
ACOUSTICS
ALLOYS
ANTIMONY ALLOYS
ELASTICITY
INVARIANCE PRINCIPLES
MAGNETIC FIELDS
MAGNETISM
MAGNETOACOUSTICS
MECHANICAL PROPERTIES
PARAMAGNETISM
PNICTIDES
RARE EARTH ALLOYS
ROTATIONAL INVARIANCE
SOUND WAVES
TENSILE PROPERTIES
THULIUM ALLOYS
VELOCITY