Annealing effects on recording characteristics of CoCr-alloy perpendicular magnetic recording media

Abstract

Annealing effects of CoCrTa and CoCrPt perpendicular magnetic recording media have been investigated. The coercivity and the squareness increase by postannealing when the annealing temperature is higher than 450 °C and CoCr35/TiCr10 dual underlayer is employed. The CoCr35 underlayer suppresses Ti diffusion to the magnetic layer and provides Cr up to the magnetic layer. The signal-to-noise ratio is improved and the magnetization irregularity diameter observed by magnetic force microscopy (MFM) decreases by the postannealing treatment.

Scanning Transmission Electron Microscopy Analysis of Grain Structure in Perpendicular Magnetic Recording Media

“…ML is deposited on a Ru layer which, like ML, has a hexagonal close-packed (hcp) crystal structure. The Ru seed layer is thought to control the ML nanostructure. ,, The grains in both ML and Ru layer exhibit strong textures with their crystallographic c axes aligned perpendicular to the thin film surface. , Understanding the structural correlation between the ML and Ru layer is important for better control of the PMR media nanostructures.…”

“…4,8,15 The grains in both ML and Ru layer exhibit strong textures with their crystallographic c axes aligned perpendicular to the thin film surface. 9,16 Understanding the structural correlation between the ML and Ru layer is important for better control of the PMR media nanostructures.…”

Aberration-Corrected Transmission Electron Microscopy of the Intergranular Phase in Magnetic Recording Media

“…10,12,13 The strongly favored growth direction of the grains creates a texture whereby c-axes of all grains are nearly perpendicular to the disk surface. 3,9,14 This is clear from the SAED pattern shown in Figure 2 which is produced solely by the crystal plane systems belonging to the [0001] zone, i.e., the {hki0} systems. The IP, on the other hand, is believed to be amorphous 4,13,15 and would not have a significant contribution in the SAED pattern other than producing a diffuse background.…”

“…The ML studied in this work is made of a CoCrPt-TiO 2 alloy with cobalt-rich magnetic grains and an oxygen-rich nonmagnetic IP, which is ideally of a different phase and composition than the ML grains. ,,, (The IP is referred to as the “grain boundary” in the background literature. ) − Co and Pt are the main constituents of the HCP-structured crystalline grains, as depicted in the selected area electron diffraction (SAED) pattern given in Figure , while Ti and O are segregated to the IP during grain growth. ,, The strongly favored growth direction of the grains creates a texture whereby c -axes of all grains are nearly perpendicular to the disk surface. ,, This is clear from the SAED pattern shown in Figure which is produced solely by the crystal plane systems belonging to the [0001] zone, i.e., the {hki0} systems. The IP, on the other hand, is believed to be amorphous ,, and would not have a significant contribution in the SAED pattern other than producing a diffuse background.…”

Microstructure and Magnetic Properties of Ag/Fe/Ag Pseudo-Sandwich Nanogranular Films

“…In situ annealing was an approach to improve magnetic properties by controlling the microstructure [30,31]. By annealing process, the lattice mobility of the atoms was enhanced, and the lattice relaxed to a more energetically favorable state.…”