Phase transitions and magnetic properties of LuFe2O4 under pressure

Abstract : The effect of hydrostatic pressure on complex magnetic phase diagram of LuFe2O4 has been investigated by various magnetic measurements in the range of 0-12 kbar. The temperature of the ferrimagnetic (fM) transition (T-N approximate to 245 K) practically does not change with increasing pressure, while the temperature of the appearance of mixed fM and antiferromagnetic (AFM) state at similar to 200 K increases with the rate dT(C)/dP approximate to 0.8 K/kbar. Moreover, an applied pressure suppresses the magnetization, enhances the field of metamagnetic transition, and extends the range of existence of mixed fM and AFM state. Suppression of the ordered magnetic moment under pressure induces a transition from a counterclockwise (CCW) thermal hysteresis below T approximate to 220 K to a clockwise (CW) thermal hysteresis in a magnetic field H = 1 kOe. Nevertheless, field induced metamagnetic transition from mixed fM and AFM state to fM state results in a narrowing of the temperature range of thermal hysteresis and in restoring of CCW type of thermal hysteresis. As a consequence of metamagnetic transition, the thermal hysteresis completed at H = 10 kOe remains one of the CCW type under applied pressure.