Structure and Magnetization of Strontium Hexaferrite (SrFe12O19) Films Prepared by Pulsed Laser Deposition

Abstract

M-type strontium hexaferrite (SrM) thin films show excellent magnetic properties and uniaxial magnetic anisotropy. We systematically investigated the magnetism of SrM films prepared by pulsed-laser deposition on different substrates [Al2O3 (11¯02), SrTiO3 (100), ZnO (0001), and LiNbO3 (0001)] at vacuum (10−4 Pa) and a substrate temperature of 800°C. Prepared films were annealed in air at a temperature of 1,000°C for 2 hours. This investigation determined the effect of annealing and different substrates on the morphology, strain, and hysteresis loops of the films. The prepared films were characterized using x-ray diffractometry, Raman spectroscopy, scanning electron microscopy, and superconducting quantum interference device (SQUID) magnetometry. X-ray diffraction analyses confirmed c-oriented growth along the out-of-plane direction in most films. We found that annealing causes enhanced crystallization in films and a significant increase in coercivity. The highest coercivity of ∼11 KOe was measured for the film deposited on the Al2O3 (11¯02) substrate.

Structural, Magnetic, and Magneto-Optical Properties of Thin Films of BaM Hexaferrite Grown by Laser Molecular Beam Epitaxy

“…Intensive studies of films and nanostructures based on hexaferrites continue to the present. Recent papers on this topic, in particular, present the results of studying strontium hexaferrite (SrFe 12 O 19 ) films obtained by pulsed laser deposition [ 32 ], the effect of La substitution on the structural and chemical properties of barium hexaferrite [ 33 ], the magnetic properties of nanostructured BaFe 12 O 19 synthesized by sol–gel spontaneous combustion [ 34 ], mechanical regulation magnetic properties of uniaxial anisotropic thin films of hexaferrite [ 35 ] etc. The main objectives of presented article were fabricating epitaxial thin (with thickness h = 50–500 nm) films of hexaferrite BaM (BaFe 12 O 19 ) grown by laser molecular beam epitaxy on α-Al 2 O 3 (0001) substrates, studying the chemical composition, surface morphology, crystal structure, static and dynamic magnetic properties, and magneto-optical spectroscopy.…”