Hexagonal barium ferrite films on a Pt(1 1 1)/Si(0 0 1) substrate and their local magnetic properties

Abstract

Abstract Hexagonal barium ferrite films were deposited on Pt(1 1 1)/Si(0 0 1) substrates by pulsed laser deposition. This paper presents an investigation of the crystal structure, morphology and local magnetic properties of the deposited films. The characterization results demonstrated orientation and morphological dependences on the Pt thickness and annealing temperature. A film prepared with a 200-nm-thick Pt buffer layer and an annealing temperature of 900 °C exhibited oriented platelet grains with a mean diameter of ∼400 nm and excellent magnetic properties with a saturation magnetization of ∼311 emu/cm3, a uniaxial anisotropy field of ∼15.5 kOe and a remanent squareness in the out-of-plane direction of ∼68.6%. Furthermore, a first-order reversal curve (FORC) diagram showed that the film had a positive mean interaction field (Hu) between particles and broad distributions of coercivity (Hc) centred at Hu = 600 Oe and Hc = 2500 Oe.