Structural transition and magnetic properties of high Cr-doped BiFeO3 ceramic

Abstract

Magnetic properties of BiFe1-xCrxO3 perovskite-type solids reaction synthesized at high pressure were investigated and a magnetic phase diagram was established. X-ray diffraction data revealed a crystal structure transformation from rhombohedral to monoclinic as Cr3+ ions substituted Fe ions in the samples. Néel temperature TN and spin-reorientation temperature TSR were determined from dM/dT by measuring the temperature dependence of magnetization (M-T). The magnetization results indicated that TN and TSR were strongly dependent on Cr3+ ion doping; both TN and TSR decreased with the increase of Cr3+ doping. The magnetic hysteresis loops investigated at room temperature reflected an antiferromagnetic behavior from x= 0.4 to 0.6 and weak ferromagnetic at x=1.0. Besides, the remnant magnetization Mr and maximum magnetization Mmax increased with increasing x from 0.4 up to 1.0. The Cr doping was found to be helpful in reducing coercivity Hc for the magnetic samples from x= 0.4 to 0.8 and their applications as magnetic sensors are possible.