Popis: |
Ln 2 BaPdO 5 (Ln = La, Pr, Nd, Sm, Eu, Gd, Dy, Ho) all crystallizes in Nd 2 BaZnO 5 structure which is proposed to have a Shastry–Sutherland (S–S) lattice of Ln 3+ ions. Ln 2 BaPdO 5 (Ln = Nd, Sm, Gd, Dy, Ho) exhibits antiferromagnetic transitions at temperatures between 2 and 5 K. In addition, metamagnetic transitions have been observed for Ln 2 BaPdO 5 (Ln = Nd, Dy, Ho) below 2 K. Specific heat of Ln 2 BaPdO 5 (Ln = Ho, Dy) exhibits symmetric peaks at T N , and residual entropy below T N is negligibly small. On the contrary, specific heat of Ln 2 BaPdO 5 (Ln = Nd, Sm, Gd) exhibits Schottky type anomalies followed by sharp peaks at T N , and residual entropy below T N is large. From these results, the applicability of the S–S model to Ln 2 BaPdO 5 with various Ln 3+ ions is proposed. |