Origin of Anisotropic Magnetic Properties in the Ferromagnetic Semiconductor CrSbSe3 with a Pseudo-One-Dimensional Structure

Low-dimensional ferromagnetic (FM) semiconductors have attracted much attention because of their novel physical properties. CrSbSe3 is a typical structurally pseudo-one-dimensional (1D) FM semiconductor. In this work, we systematically investigated the anisotropy of magnetic properties and magnetic entropy change in the CrSbSe3 single crystal. There are some observations: (1) the crystal with a needle-like shape shows the paramagnetic-FM (PM-FM) transition (T-C) around 71 K, and the easy axis is the a axis perpendicular to the crystalline chain; (2) the largest magnetic entropy is about 2.2 J/kg K with the applied magnetic field H = 4.5 T along the c axis. Meanwhile, anisotropy of magnetic entropy change of Delta S-M(T,H) shows that the differences of -Delta S-M(max)(T,H) are 0.32 J/(kg K) (between the a and b axis), 0.18 J/(kg K) (between the a and c axis), and nearly zero (between the b and c axis) for the applied magnetic field H = 4.5 T. (3) The calculated uniaxial anisotropy parameter K-u decreases monotonically from 22 kJ/m at 5 K to 5 kJ/m near T-C for the H//a axis, 168 kJ/m at 5 K to 35 kJ/m near T-C for the H//b axis, and 50 kJ/m at 5 K to 10 kJ/m near T-C for the H//c axis, respectively. The existence of magnetic correlation around T-g approximate to 200 K (above the T-C) has been observed. The collective interaction between the magnetic correlations above T-C accompanied by the strong magnetocrystalline anisotropy below T-C plays an important role in the origin of the abnormal ferromagnetism in CrSbSe3. Our observations may provide a typical reference to investigate the anomalous behavior in some of the low-dimensional FM semiconductors with unconventional PM-FM transitions.