Low-temperature magnetic phase diagram of HoFe(3)(BO(3))(4) holmium ferroborate: a magnetic and heat capacity study.

We present the results of the magnetic and heat capacity study of a magnetic phase diagram of a HoFe(3)(BO(3))(4) single crystal. Two magnetic phase transitions are found in the low-temperature region. The transition from the paramagnetic to easy-plane antiferromagnetic state occurs at T(N) = 37.4 K and is independent of an applied magnetic field. The sharp heat capacity peaks and magnetization jumps corresponding to the spontaneous and field-induced spin-reorientation transitions between the easy-axis and easy-plane states are observed below 4.7 K. Also, the additional heat capacity peaks, which can be attributed to the Schottky anomalies with the field-dependent characteristic temperatures, are found. According to the magnetic and thermal measurement data, the magnetic phase diagrams of HoFe(3)(BO(3))(4) for the magnetic field parallel and perpendicular to the crystal axis are constructed.