skip to main content

Title: Microstructure investigations of hcp phase CoPt thin films with high coercivity

CoPt films have been grown in the past with a high anisotropy in L1{sub 1} or L1{sub 0} phase, and a high coercivity is observed only in L1{sub 0} CoPt films. Recently, we have grown CoPt films which exhibited a high coercivity without exhibiting an ordered phase. In this study, high resolution transmission electron microscopy (HRTEM) investigations have been carried out to understand the strong thickness and deposition pressure dependent magnetic properties. HRTEM studies revealed the formation of an initial growth layer in a metastable hexagonal (hcp) CoPt with high anisotropy. This phase is believed to be aided by the heteroepitaxial growth on Ru as well as the formation of Ru-doped CoPt phase. As the films grew thicker, transformation from hcp phase to an energetically favourable face-centered cubic (fcc) phase was observed. Stacking faults were found predominantly at the hcp-fcc transformation region of the CoPt film. The higher coercivity of thinner CoPt film is attributed to relatively less fcc fraction, less stacking faults, and to the isolated grain structure of these films compared to the thicker films.
Authors:
; ; ; ;  [1]
  1. Data Storage Institute, A-STAR (Agency for Science, Technology and Research), 5, Engineering Drive 1, Singapore 117608 (Singapore)
Publication Date:
OSTI Identifier:
22277981
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; COBALT ALLOYS; COERCIVE FORCE; COMPARATIVE EVALUATIONS; CRYSTAL GROWTH; DOPED MATERIALS; FCC LATTICES; HCP LATTICES; INTERMETALLIC COMPOUNDS; LAYERS; MAGNETIC PROPERTIES; MICROSTRUCTURE; PLATINUM ALLOYS; PRESSURE DEPENDENCE; RUTHENIUM ALLOYS; STACKING FAULTS; THICKNESS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY