Lattice defects related magnetic and magnetocapacitance properties of multiferroic BaFe10.2Sc1.8O19 epitaxial thin films

Without changing the crystalline structure of BaFe10.2Sc1.8O19 (BFSO) epitaxial thin film, significant modulation of its saturation magnetization (from 75 to 180 emu/cc), magnetic anisotropy field (from 3590 to 1434 Oe) and multiferroic ordering temperature (from 207 to 306 K) can be realized with different densities of lattice defects (DLD). A defects-related effective magnetic field H-eff is defined. H-eff reduces obviously with increasing annealing temperature T-A, agreeing well with the reduced DLD. The defects-related magnetic ordering of BFSO films is further verified in the magnetocapacitance devices. The magnetocapacitance for 1000 degrees C annealed film is more than 5 times larger than that of as-deposited film. This can be explained by the ultra-sensitive of non-collinear conical magnetic structure and spin-phonon coupling in BFSO to the DLD related local lattice structure. The above findings enable better understanding and usage of lattice defects on regulating the physical properties of multiferroic hexaferrite devices. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

Significant modulation of saturation magnetization, magnetic anisotropy field, and multiferroic ordering temperature can be achieved in BaFe10.2Sc1.8O19 (BFSO) epitaxial thin film by introducing different densities of lattice defects. The defects-related magnetic field decreases with increasing annealing temperature, in accordance with the reduced density of lattice defects. The findings provide important insights into regulating the physical properties of multiferroic hexaferrite devices through lattice defects.