Magnetic phase transitions in α-CeS2

• Published in: Journal of applied physics 1991-04, Vol.69 (8), p.4630-4632
• Main Authors: KLIMENKO, A. G, ISHIKAEV, S. M, TAGAEV, A. B, VASILYEVA, I. G, KARPENKO, M. M, FISCHER, P, FURRER, A, STAUB, U
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Physics
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.348304

Physical properties of platelike single crystals (size up to 3×0.2×2 mm3, b axis perpendicular to the plate) of α-CeS2 (monoclinic, space group P21/c) have been studied and magnetic ordering was found below 7 K. Specific heat Cp(T) has a λ-type anomaly at TN=6.7 K with entropy sm=0.94R ln 2 and an additional maximum at 6.0 K (S′m ∼ 0.02R ln 2). Crystal-field splitting of the 2F5/2 state of Ce3+ into three doublets with energy levels 0, 230, and 415 cm−1 was obtained from Cp(T). Magnetic properties were studied using SQUID and vibrating sample magnetometer. Paramagnetic susceptibility obeys a Curie–Weiss law with anisotropic effective magnetic moment and Curie–Weiss temperature: P=2.1 μB, Θ=+7.8 K for b axis and P=1.5 μB, Θ=−0.8 K in directions perpendicular to the b axis. Complicated magnetic behavior is observed in low fields (0.1–100 Oe) below TN (strong dependence of dc susceptibility on thermomagnetic prehistory, cooling rate and applied field, remanent and memory phenomena). Magnetization curves at 4.2 K show a sharp metamagnetic transition at Hc=5 kOe for a field along the b axis and linear dependence M(H) up to 30 kOe for the perpendicular direction. Neutron scattering experiments are in progress to establish details of the magnetic structure and the crystal-field splitting.