Wei Li, 1 Shou-Shu Gong, 1 Yang Zhao, 1 Shi-Ju Ran, 1 Song Gao, 2 and Gang Su 1, *
¹ College of Physical Sciences, Graduate University of Chinese Academy of Sciences, P.O. Box 4588, Beijing 100049,
People’s Republic of China
² College of Chemistry and Molecular Engineering, State Key Laboratory of Rare Earth Materials Chemistry and Applications,
Peking University, Beijing 100871, People’s Republic of China
(Received 8 July 2010; revised manuscript received 24 September 2010; published 21 October 2010)

Abstract:

The two-dimensional Ising model on a distorted kagome lattice is studied by means of exact solutions and the tensor renormalization-group (TRG) method. The zero-field phase diagrams are obtained, where three phases such as ferromagnetic, ferrimagnetic, and paramagnetic phases, along with the second-order phase transitions, have been identified. The TRG results are quite accurate and reliable in comparison to the exact solutions. In a magnetic field, the magnetization (m), susceptibility, and specific heat are studied by the TRG algorithm, where the m=1/3 plateaux are observed in the magnetization curves for some couplings. The experimental data of susceptibility for the complex Co(N₃)₂ (bpg)·DMF_4/3 are fitted with the TRG results, giving the couplings of the complex J=22 K and J' =33 K.