Abstract
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.
Highlights
A series of RTr2X20 (R = rare-earth element, Tr = transition metal element, X = Al, Zn, Cd) of intermetallic compound crystallizes in the cubic CeCr2Al20 -type structure with a space group Fd3 ̄m (No 227)
The temperature dependence of the electrical resistivity shows a shoulder-like structure around 10 K, possibly indicating the reduction of crystalline electric field (CEF) excitation of 4f electrons
It should be noted that the specific heat divided by temperature increases with decreasing temperature even below T c and attains 4.5 J/mol K2 at 0.26 K, suggesting formation of the heavy fermion (HF) state and possibly strong magnetic quantum fluctuations
Summary
A series of RTr2X20 (R = rare-earth element, Tr = transition metal element, X = Al, Zn, Cd) of intermetallic compound crystallizes in the cubic CeCr2Al20 -type structure with a space group Fd3 ̄m (No 227). In this structure, the rare-earth atoms occupy the 8a site with cubic T d symmetry located at the center of an X16 cage (CN 16 Frank-Kasper polyhedron), forming a diamond structure sublattice.[1] Among the series, Sm-based systems SmTr2X20 exhibit often unusual magnetic-fieldinsensitive heavy fermion (HF) behavior, being markedly different from those of Ce-based HF ones. We report the low-temperature property of SmPt2Cd20 proved by ultrasound measurements
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
