Abstract: Multiferroic materials can realize the mutual coupling between force, electricity, magnetism and other physical fields, and have important application prospects in the field of small size, fast response and low power consumption of magnetoelectric devices. GaFeO₃ is a highly promising multiferroic material featuring high spontaneous magnetization and polarization beyond room temperature. In this study, Ferroelectric Mg_xGa_1-xFeO₃ (x=0.02, 0.05, 0.07 and 0.10) single crystals with a diameter of about 7 mm were grown by light floating zone method. The effect of Mg²⁺ on the saturation magnetization and magnetic transition temperature of GaFeO₃ (GFO) crystals were studied. The structure and phase of the crystal were analyzed through XRD, the results show that all the prepared samples correspond to the diffraction characteristics of the standard crystal card library GFO (PDF#76-1005), and no other heterophase appears. The XRD refinement results indicate that, the crystal structure is orthogonal and its space group is Pna2₁. As the concentration of Mg²⁺ rises, the lattice constant and cell volume initially increase and subsequently decrease. Additionlly, the magnetic properties of the crystal were studied through a comprehensive physical property measurement system, the magnetic transition temperature and saturation magnetization of the grown crytals also increase firstly and then decrease with the increase of Mg²⁺ doping content. When the Mg²⁺ doping amount is 0.07, the magnetic transition temperature and saturation magnetization reach the maximum values of 187.82 K and 8.75 emu/g, respectively, which achieves the purpose of doping modification.

Key words: ferroelectric single crystal, GaFeO₃∶Mg, optical floating zone method, saturation magnetization, magnetic transition temperature, coercive field