Ferroelectric and ferromagnetic properties of BiFeO3-PrFeO3-PbTiO3 solid solutions

Solid solutions of xBiFeO(3-y)PrFeO(3)-zPbTiO(3) (x+y+z=1) and (1-w)BiFeO3-wPbTiO(3) have been explored for finding ferroelectromagnetic bulk material, in which ferroelectricity and ferromagnetism, coexist simultaneously. the coexistence has been observed only in some ternary composition samples, that is, 0.2BiFeO(3)-.0.2PrFeO(3)-0.6PbTiO(3). and 0.4BiFeO(3)-0.2PrFeO(3)-0.4PbTiO(3). In the ternary solid solutions, spontaneous magnetic moments disappear with the decrease of PrFeO3 content to y<0.2 independently of BiFeO3 content. When PrFeO3 content remains constant at y = 0.2, the ternary solid solutions become paraelectric with the decrease of PbTiO3 content to z ≤ 0.2. The. ferroelectromagnetic solid solutions have the noncentrosymmetric and doubled perovskite unit cell with a space group I4cm (a = b ≈ 5.4 &ANGS;, c ≈7.9 &ANGS;). Addition of Ta2O5 dopant substantially changes the polarization-electric-field and magnetization-magnetic field curves of the 0.2BiFeO(3)-0.2PrFeO(3)-0.6PbTiO(3). The binary solid solutions of (1-w)BiFeO3-wPbTiO(3) do not exhibit spontaneous magnetic moments down to 10 K over the entire composition range. (C) 2003 American Institute of Physics.