Magnetization and specific heat measurement of the Shastry-Sutherland lattice compounds : Ln2BaPdO5 (Ln = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho)

• Published in: Journal of alloys and compounds 2008-01, Vol.448 (1-2), p.96-103
• Main Authors: OZAWA, T. C, TANIGUCHI, T, KAWAJI, Y, MIZUSAKI, S, NAGATA, Y, NORO, Y, SAMATA, H, MITAMURA, H, TAKAYANAGI, S
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Critical-point effects, specific heats, short-range order; Exact sciences and technology; Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.); Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Physics; Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2007.05.036

Ln2BaPdO5 (Ln=La, Pr, Nd, Sm, Eu, Gd, Dy, Ho) all crystallizes in Nd2BaZnO5 structure which is proposed to have a Shastry-Sutherland (S-S) lattice of Ln3+ ions. Ln2BaPdO5 (Ln=Nd, Sm, Gd, Dy, Ho) exhibits antiferromagnetic transitions at temperatures between 2 and 5K. In addition, metamagnetic transitions have been observed for Ln2BaPdO5 (Ln=Nd, Dy, Ho) below 2K. Specific heat of Ln2BaPdO5 (Ln=Ho, Dy) exhibits symmetric peaks at TN, and residual entropy below TN is negligibly small. On the contrary, specific heat of Ln2BaPdO5 (Ln=Nd, Sm, Gd) exhibits Schottky type anomalies followed by sharp peaks at TN, and residual entropy below TN is large. From these results, the applicability of the S-S model to Ln2BaPdO5 with various Ln3+ ions is proposed.