Dielectric, ferroelectric, magnetic and electrical properties of Sm-doped GaFeO3

The effect of Sm doping on structural, dielectric, multiferroic and electrical properties of GaFeO3 with composition GaFe1-xSmxO3 (x = 0, 0.05, 0.10, 0.15) is studied. Rietveld refinement of the XRD data reveals the formation of single-phase orthorhombic structure. It is observed that the unit cell volume increases with rise in Sm content. FESEM study reveals that the irregular-shaped grains are uniformly distributed throughout the surface. From dielectric plot, a significant variation in epsilon(r) and tan delta with Sm content is observed. Further, conjugate existence of both ferroelectric and magnetic ordering is confirmed by polarisation and magnetization hysteresis loop measurement. The remanent polarisation (P-r) is decreased with Sm content due to the defects related to fluctuations in the valance of Fe in the studied samples. Also, the remanent magnetization (M-r) is found to fall with rise in Sm content due to the lower magnetic moment (mu) of Sm3+. Impedance analysis shows the existence of two types of relaxation in studied materials.