Fermi-surface topologies and low-temperature phases of the filled skutterudite compounds CeOs4Sb12 and NdOs4Sb12

• Published in: Physical review. B 2016-11, Vol.94 (20)
• Main Authors: Ho, Pei Chun, Singleton, John, Goddard, Paul A, Balakirev, Fedor F, Chikara, Shalinee, Yanagisawa, Tatsuya, Maple, M Brian, Shrekenhamer, David B, Lee, Xia, Thomas, Avraham T
• Format: Article
• Language: English
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; De Haas-Van Alphen effect; Dependence; Fermi surfaces; High Magnetic Field Science; High Magnetic Fields; Low temperature; Phase transitions; quantum criticality; Shubnikov de Haas effect; Single crystals; skutterudites; Topology; Torque magnetometers
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.94.205140

MHz conductivity, torque magnetometer, and magnetization measurements are reported on single crystals of CeOs4Sb12 and NdOs4Sb12 using temperatures down to 0.5 K and magnetic fields of up to 60 tesla. The field-orientation dependence of the de Haas-van Alphen and Shubnikov-de Haas oscillations is deduced by rotating the samples about the [010] and [01¯1] directions. The results indicate that NdOs4Sb12 has a similar Fermi surface topology to that of the unusual superconductor PrOs4Sb12, but with significantly smaller effective masses, supporting the importance of local phonon modes in contributing to the low-temperature heat capacity of NdOs4Sb12. By contrast, CeOs4Sb12 undergoes a field-induced transition from an unusual semimetal into a high-field, high-temperature state characterized by a single, almost spherical Fermi-surface section. The behavior of the phase boundary and comparisons with models of the band structure lead us to propose that the field-induced phase transition in CeOs4Sb12 is similar in origin to the well-known α−γ transition in Ce and its alloys.