Effects of Structural Collapse and Magnetic Moment on Magnetization in ${\rm Bi}_{0.8-{\rm x}}{\rm Pr}_{\rm x}{\rm Ba}_{0.2}{\rm FeO}_{3}$ $({\rm x}\leq 0.1)$ Multiferroics

The structural, magnetic, and ferroelectric properties of polycrystalline Bi
_0.8-x
Pr
_x
Ba
_0.2
FeO
₃
(0.0 ≤ x ≤ 0.1) ceramics are studied systematically. The symmetry of the unit cell with Ba and Pr substitution in BiFeO
₃
in the substitution range remains the cubic with the space group of
Pm
3
m
. The additive of Pr in (BiBa)FeO
₃
reduces the unit cell volume together with varying the lattice parameters without changing the unit cell symmetry. The distortion of FeO
₆
octahedron resulting from the additive of Pr may induce the collapse of the spatial spin structure, which may enhance the spontaneous magnetization significantly. The remnant magnetization (
Mr
) increases monotonically with increasing the content of Pr, which probably originates from the ferromagnetic arrangement of Pr-ions and Fe-ions in the unit cell. The conductivity increases in a wide temperature regime result in an obvious leakage observed with increasing the Pr concentration.