Ferroelectric and ferromagnetic properties of Co doped BiFeO_3 thin films

摘要

Materials which possess electrical and magnetic coupling are of great interest for novel devices. Bi(Fe_(1-x)Co_x)O_3 (BFCO) material system was synthesized by solution route for various compositions and thin films were prepared by spin coating on Pt (Pt/Ti/SiO_2/Si) substrates. Structural properties of the films were investigated by x-ray diffraction and Raman spectroscopy. X-ray diffraction patterns confirms intense (110) in BiFeO_3 and Bi(Fe_(1-x)Co_x)O_3 with rhombohedra distorted perovskite structure without impure phase. Bi(Fe_(1-x)Co_x)O_3 films show week ferroelectric polarization and ferromagnetism at room temperature. Ferroelectric and ferromagnetic coupling could be attributed to the elimination of oxygen vacancies and increased stress in the crystal structure by partial replacement of Fe~(2+) ion by Co~(2+) ion.