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Title: Effects of Co layer thickness and annealing temperature on the magnetic properties of inverted [Pt/Co] multilayers

The effects of Co layer thickness and annealing temperature on the perpendicular magnetic anisotropy (PMA) properties of inverted [Pt (0.2 nm)/Co (t{sub Co})]{sub 6} multilayers (where t{sub Co} indicates the thickness of the Co layer) have been investigated. The cross-sectional microstructure, as observed from the high-resolution transmission electron microscope images, shows a clear layered structure with atomically flat interfaces both in the as-deposited state as well as after annealing, indicating the interface effects for PMA. The effective PMA energy density (K{sub eff}) increases significantly with an increase in t{sub Co} from 0.2 to 0.28 nm and then becomes almost saturated with further increases in t{sub Co}, followed by a slight reduction at the highest Co thickness, t{sub Co} = 0.6 nm. In order to explain the t{sub Co} dependence on K{sub eff}, the intrinsic PMA energy density (K{sub i}) is calculated by additionally measuring a similar set of results for the saturation magnetization. The K{sub i} value increases nearly linearly with the increase in t{sub Co} from 0.2 to 0.5 nm, followed by saturation at a higher t{sub Co} value of 0.6 nm. Owing to a close relationship between K{sub i} and the quality of the interfaces, these results indicate a similar t{sub Co} dependence on themore » quality of the interfaces. This is further supported from the magnetic measurements of the samples annealed at the highest temperature of 500 °C, where a second phase is formed, which show a similar t{sub Co} dependence on the amount of the second phase. The K{sub i} value is nearly independent of the annealing temperature at t{sub Co} ≤ 0.4 nm, above which a substantial reduction is observed, when the annealing temperature exceeds 500 °C.« less
Authors:
;  [1] ; ;  [2] ;  [1] ;  [3]
  1. Department of Nano Semiconductor Engineering, Korea University, Seoul 136-713 (Korea, Republic of)
  2. Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of)
  3. (Korea, Republic of)
Publication Date:
OSTI Identifier:
22257799
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 17; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; ANNEALING; DEPOSITS; ENERGY DENSITY; IMAGES; MAGNETIC PROPERTIES; MAGNETIZATION; MICROSTRUCTURE; SATURATION; THICKNESS; TRANSMISSION ELECTRON MICROSCOPY