Specific Heat Study of Multiferroic LuFe₂O₄ Single Crystal

Abstract

Precise measurements of specific heat were performed on high quality single crystals of multiferroic LuFe₂O₄ by using an ac calorimeter. The thermal anomalies corresponding to four known phase transitions were observed at 220 K (T_g), 260 K (T_N), 380 K (T_3CO) and 590 K (T_2CO). In addition to them, a new clear anomaly was detected at 305 K. No other distinct anomaly could be observed below 220 K down to 100 K. It is clarified that the temperature dependence of the order parameter associated with this new phase transition at 305 K is quite similar to those of spontaneous polarization reported previously by Ikeda et al.

Keywords:

• LuFe₂O₄
• multiferroic
• heat capacity
• order parameter
• phase transition