Magnetic phase transitions in HoFeO_3 single crystals grown using the optical floating-zone method

摘要

We have successfully grown high-quality single crystals of potential multiferroic orthoferrite HoFeO_3 in a four-mirror optical floating-zone furnace under two different grown atmospheres, namely, argon and air. The magnetic susceptibilities of both the crystals were measured in the temperature range 2 K to 300 K parallel to their principal crystallographic axes. Both crystals exhibit spin-reorientation of Fe~(3+) spins from c-axis towards a-axis in the temperature range 50 - 60 K, although there is a small difference in the magnitude of the moments. The Neel ordering temperature (T_N~ 640 K) of Fe-spin is also revealed in high temperature magnetic measurements, independent of the growth atmosphere.