Magnetic and Transport Properties of Single-Crystal YbPtGe

• Published in: Journal of the Physical Society of Japan Vol. 78; no. 10; p. 104721
• Main Authors: KATOH, Kenichi, NAKAGAWA, Seisuke, TERUI, Giichi, OCHIAI, Akira
• Format: Journal Article
• Language: English
• Published: Tokyo Physical Society of Japan 01-10-2009; The Physical Society of Japan
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain effects, magnetization curves, and hysteresis; Electronic conduction in metals and alloys; Electronic transport in condensed matter; Exact sciences and technology; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Magnetocaloric effect, magnetic cooling; Physics; Scattering mechanisms and kondo effect; YbPtGe; Electrical conductivity; Magnetization; heavy-fermion; Heavy fermions; Sommerfeld constant; Crystal field; Magnetic transitions; Platinum Ytterbium Germanides Mixed; Specific heat; Schottky anomalies; Monocrystals; Magnetocaloric effects; Anisotropy; Orthorhombic lattices; Transport processes; Ferromagnetic-paramagnetic transitions; electrical resistivity; Magnetic properties
• ISSN: 0031-9015; 1347-4073
• DOI: 10.1143/jpsj.78.104721

The magnetic and transport properties of single-crystal YbPtGe with the TiNiSi-type orthorhombic structure are presented. It is revealed that YbPtGe is a ferromagnet with TC=5.4 K. Although both of its paramagnetic and ferromagnetic states show uniaxial anisotropy, its easy axis changes from the a-axis in the paramagnetic state to the c-axis below TC. Magnetizations at 2 K along the a-, b-, and c-axes saturate to constant values of 1.5 μB for 6 kOe, 0.55 μB for 2 kOe, and 1.1 μB for 1 kOe, respectively. The magnetic contribution to the specific heat shows a Schottky anomaly centered at 90 K due to the crystalline electric field (CEF) effect that splits the eight-hold J-multiplet of the Yb3+ ion into four doublets. The Sommerfeld coefficient γ is estimated to be 209 mJ/(mol·K2) below TC. The magnetic entropy released up to TC is 52% of that of Rln2, expected for the doublet ground state. Therefore, YbPtGe is a middle-classed heavy-fermion compound with a ferromagnetic transition.