Structure, Morphology, and Magnetic Properties of New Multiferroic Nanocomposite Obtained by High-Pressure Torsion

Abstract

Structure, morphology, chemical composition, and magnetic properties of the new multiferroic nanocomposite have been investigated by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and magnetic methods. The $0.8\mathbf{Bi}_{0.9}\mathbf{La}_{0.1}\mathbf{FeO}_{3}-0.2\mathbf{Mn}_{0.6}\mathbf{Zn}_{0.3}\mathbf{FeO}_{4}$ nanocomposite has been prepared by the high-pressure torsion method from the powder mixture consisting of 80 wt.% $\mathbf{Bi}_{0.9}\mathbf{La}_{0.1}\mathbf{FeO}_{3}$ and 20 wt.% $\mathbf{Mn}_{0.6}\mathbf{Zn}_{0.3}\mathbf{FeO}_{4}$. According to the structural data, the particle size of the initial stochiometric powders decreases dramatically from 131 to 14 nm for the $\mathbf{Bi}_{0.9}\mathbf{La}_{0.1}\mathbf{FeO}_{3}$ fractions and from 15 to 12 nm for the $\mathbf{Mn}_{0.6}\mathbf{Zn}_{0.3}\mathbf{FeO}_{4}$ fractions after the high-pressure torsion. Based on the analysis of the magnetic data, the $\mathbf{Bi}_{0.9}\mathbf{La}_{0.1}\mathbf{FeO}_{3}$ multiferroic and $\mathbf{Mn}_{0.6}\mathbf{Zn}_{0.3}\mathbf{FeO}_{4}$ ferrospinel show weak and strong ferromagnetic behaviors, respectively. The combination of the multiferroic $\mathbf{Bi}_{0.9}\mathbf{La}_{0.1}\mathbf{FeO}_{3}$ and ferromagnetic $\mathbf{Mn}_{0.6}\mathbf{Zn}_{0.3}\mathbf{FeO}_{4}$ phases has improved the magnetoelectric coupling of the new nanocomposite.