Phase evolution and magnetic property of Bi1−xHoxFeO3 powders

The structural, vibrational, and magnetic properties of well prepared Bi1−xHoxFeO3 (x=0x=0–0.175) powders are investigated by combining X-ray diffraction, Raman scattering, and magnetometry measurements. A structural symmetry breaking from the rhombohedral R3cR3c to orthorhombic Pnma   between x=0.10x=0.10 and 0.125 is identified from the X-ray and Raman measurements, accompanying a ferroelectric–paraelectric phase transition. The remnant magnetization of Bi1−xHoxFeO3 is enhanced before approaching the ferroelectric–paraelectric phase boundary, and then it slightly decreases until x=0.175x=0.175. Such enhancement (0≤x≤0.100≤x≤0.10) is suggested to result from the destruction of the spin cycloid structure. The decrease in the remnant magnetization with higher substitution concentration is due to the further destruction in the space modulated spin structure allowing a more perfect antiferromagnetic ordering.

► Ho subsitutes at the Bi site in BiFeO3 (Bi1−xHoxFeO3, x=0x=0–0.175).
► No secondary phase in all samples.
► Ferroelectric–paraelectric phase transition occurs at x=0.10x=0.10–0.125.
► The highest remnant magnetization is at the phase boundary.
► The destruction of spin cycloid structure leads to the magnetization enhancement.