Magnetization, Resistivity and Specific Heat of HexagonalR2Ni12P7with Filled-Cr12P7Structure

Abstract

We prepared single-crystal samples of hexagonal R 2 Ni 12 P 7 ( R = Sm, Gd–Lu) using a Sn-flux method, and measured their magnetization, resistivity, and specific heat. The antiferromagnetic order in Gd 2 Ni 12 P 7 and Ho 2 Ni 12 P 7 , the ferromagnetic order in Dy 2 Ni 12 P 7 and Er 2 Ni 12 P 7 , and the ferromagnetic-like order in Sm 2 Ni 12 P 7 , Tb 2 Ni 12 P 7 , and Tm 2 Ni 12 P 7 were evidenced by the results of the measurements. In contrast, we found that Yb 2 Ni 12 P 7 is in a heavy fermion state at low-temperature region. Hump-type anomalies in specific heat were observed below the magnetic transition temperature in R 2 Ni 12 P 7 ( R = Gd, Tb, and Dy), indicating the Zeeman splitting of the J -multiplet of the R 3+ ion in the ordered state.