Ferromagnetism and crystal electric field in the cerium compound CeRh3B2

• Published in: Journal of physics. Condensed matter 2007-09, Vol.19 (35), p.356208-356208 (11)
• Main Authors: Givord, F, Boucherle, J-X, Galéra, R-M, Fillion, G, Lejay, P
• Format: Article
• Language: English
• Subjects: Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Other ferromagnetic metals and alloys; Physics; Strongly Correlated Electrons; Studies of specific magnetic materials
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/19/35/356208

The magnetic behavior of CeRh3B2 is very unusual: it orders ferromagnetically with an exceptionally high Curie temperature TC around 115 K, but with a small saturation moment of about 0.4 muB/fu. The thermal variations of magnetization and susceptibility have been measured on a single crystal for fields applied along the easy and hard magnetization directions, with, in the latter case, special care taken to avoid rotation of the sample. The results are compared to calculations based on the crystalline electric field formalism. Due to its large value, one has to take into account the admixture of the two J multiplets of the Ce3+ ion as it is usually used for samarium compounds but not for cerium ones. These calculations actually show the important role of the excited J' = 7/2 multiplet on the 4f spin moment, leading to an enhancement of the exchange, i.e. the Curie temperature, and to a decrease of the moment. An extra polarization, as previously found from the study of magnetization density maps, is confirmed and discussed.