Elastic properties of SmPt2Cd20 probed by ultrasound measurements

• Published in: AIP advances 2018-10, Vol.8 (10), p.101337-101337-3
• Main Authors: Nakanishi, Yoshiki, Nakamura, Kazuto, Nakamura, Masahiro, Taniguchi, Masaya, Nakamura, Mitsuteru, Yoshizawa, Masahito, Yamada, Akira, Higashinaka, Ryuji, Matsuda, Tatsuma D., Aoki, Yuji
• Format: Article
• Language: English
• Subjects: Conduction electrons; Deformation mechanisms; Elastic properties; Electron states; Electrons; Ground state; Magnetic transitions; Softening; Sound waves; Temperature; Temperature dependence; Transition temperature; Ultrasonic imaging
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.5042811

Ultrasound measurements have been carried out to investigate the elastic and low-temperature 4f-electronic properties of the Sm-based 1-2-20 system SmPt2Cd20. It was found that SmPt2Cd20 shows a pronounced elastic softening toward the magnetic transition temperature Tc = 0.64 K in the temperature dependence of the transverse elastic constant CE = (C11 -C12)/2. The clear elastic softening behavior is suppressed gradually with increasing a magnetic field. The obtained results can be explained reasonably by a deformation potential approximation in which a coupling between conduction electrons and elastic strains caused by sound waves leads to a temperature dependence of elastic constants. This suggests possibly that the 4f electrons would become itinerant in the ground state in SmPt2Cd20. The nature of the low-temperature elastic and electronic states involving the ground state multiplets of Sm ions are discussed.