Anisotropic magnetic phase diagrams of HoB4 single crystal

Abstract

We have investigated the magnetic and electronic properties of a single-crystal HoB4. Antiferromagneticlike transitions were revealed by the temperature-dependent magnetization exhibiting two transition temperatures at T-N1=7.1 K and T-N2=5.7 K for an applied magnetic field along the c-axis, and showed only one transition at T=5.7 K for an applied magnetic field perpendicular to the c-axis. The isothermal magnetization with an applied magnetic field along the c-axis exhibited three distinct metamagnetic phase transitions at H-c1=2 T, H-c2=3.5 T, and H-c3=3.9 T at T=2 K. On the other hand, the isothermal magnetization with an applied magnetic field perpendicular to the c-axis showed two metamagneticlike transitions. A rapid change in the temperature and the field-dependent resistivity was found to be intimately correlated with magnetic transitions. Based on the isothermal magnetization and field-dependent resistivity for both magnetic field directions (H parallel to c and H perpendicular to c), anisotropic phase diagrams of HoB4 were constructed. From the comparison of the phase diagram of HoB4 with that of DyB4, it was deduced that HoB4 has a geometrical quadrupolar frustration of Ho3+ moment. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3075871]