Low frequency dependent elastic modulus in UCo.sub.1-x./sub.Os.sub.x./sub.Al

0539063 - FZÚ 2021 RIV JP eng C - Conference Paper (international conference)
Kumano, S. - Ishii, I. - Horio, R. - Mizuno, T. - Umeno, T. - Suzuki, D. - Andreev, Alexander V. - Gorbunov, D.I. - Yamamura, T. - Suzuki, T.
Low frequency dependent elastic modulus in UCo_1-xOs_xAl.
JPS Conference Proceedings. Vol. 30. Tokyo: Physical Society of Japan, 2020 - (Hotta, T.; Katsufuji, T.), s. 1-6, č. článku 011173. ISBN 978-4-89027-142-9. ISSN 2435-3892.
[International Conference on Strongly Correlated Electron Systems (SCES2019). Okayama (JP), 23.09.2020-28.09.2020]
R&D Projects: GA ČR(CZ) GA19-00925S
Institutional support: RVO:68378271
Keywords : UCo_1-xOs_xAl * large amplitude atomic motion * elastic modulus * ultrasonic dispersion
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)

UCoAl with the hexagonal ZrNiAl-type structure shows an itinerant metamagnetic phase transition at 0.7 T in the magnetic field along the c-axis. Compound undergoes a ferromagnetic phase transition in zero field by substituting Os for Co. UCo0.995Os0.005Al exhibits the ferromagnetic phase transition at TC = 8 K. At high temperatures, the temperature dependence of the transverse elastic modulus C44 in UCo0.995Os0.005Al shows a slight softening below 50 K. The softening turns to an abrupt hardening below 30 K. With further decreasing temperature, a bending is observed at TC. The elastic hardening is not caused by a magnetic origin. We measured ultrasonic frequency dependences of C44 and found that the temperature of the elastic hardening increases with increasing ultrasonic frequency. We propose that this ultrasonic frequency dependence is due to a large amplitude atomic motion of constituent atoms.

Permanent Link: http://hdl.handle.net/11104/0316817