Structural and multiferroic properties of Bi0.92−x Ho0.08Sr x Fe0.97Mn0.03O3 thin films

Abstract

The Bi0.92−x Ho0.08Sr x Fe0.97Mn0.03O3(BHSr x FMO) thin films were deposited on FTO/glass substrates by the sol–gel method. The structure, surface morphologies, and electric properties of the thin films were investigated. The results show that the structure of BHSr x FMO thin films transformed from rhombohedral R3c:H to rhombohedral R3m:R when doped with the Sr2+ ions. When the ferroelectric domain structure of the BHSr x FMO(x = 0.00–0.04) thin films is converted from ferroelectric phase and antiferroelectric phase to ferroelectric phase, the coercive field (E c) increased. This change occurs when the defect dipole of $$ ({\text{Sr}}_{{_{{\text{Bi}}} }}^{{\prime }} - {\text{V}}_{{\text{O}}}^{ \cdot \cdot } )^{ \cdot } $$ of BHSr x FMO thin films increased, which clamps the domain wall motion and changes the directions of spontaneous polarization. In an electric field of 536 kV/cm, the 2P r and 2E c of BHSr3FMO thin film are 81.9 μC/cm2 and 524 kV/cm, respectively. In the magnetic field of 8000 Oe, the magnetization of the BHSr3FMO thin film is 8.34 emu/cm3. The BHSr3FMO thin film shows the great multiferroic properties, which are mainly connected with the rhombohedral structure of R3c:H (51%)/R3m:R(49%) space groups at morphotropic phase boundary.