Magnetic, structural and microstructural properties of FePt/M (M=C,BN) granular films

Author

Christodoulides, J.A. ; Farber, P. ; Dannl, M. ; Okumura, H. ; Hadjipanaysi, G.C. ; Skumryev, V. ; Simopoulos, A. ; Weller, D.

Author_Institution

Dept. of Phys. & Astron., Delaware Univ., Newark, DE, USA

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

1292

Lastpage

1294

Abstract

Nanocomposite FePt/C and FePt/BN thin films have been fabricated by dc and rf magnetron sputtering on naturally-oxidized Si(100) substrates. Particles consisting of the highly anisotropic tetragonal L1 ₀ FePt phase were obtained by annealing the as-made multilayers by a conventional vacuum furnace in the temperature range of 500 to 800°C. By controlling the annealing conditions, samples with grain size in the range of 3 to 20 nm were obtained, with coercivities between 2 and 16 kOe. The evolution of crystal structure during annealing at 600°C was studied in FePt/C and the dependence of a, c and c/a on annealing time were determined. These data were used to estimate the degree of ordering which was found to increase with aging, but with a maximum value less than the bulk value, explaining thus the lower H_c in the nanoparticles

Keywords

ageing; annealing; boron compounds; carbon; coercive force; composite materials; grain size; granular materials; iron alloys; magnetic anisotropy; magnetic multilayers; magnetic particles; magnetic thin films; nanostructured materials; platinum alloys; sputtered coatings; 500 to 800 C; DC magnetron sputtering; FePt particles; FePt-BN; FePt-C; RF magnetron sputtering; Si(100) substrate; aging; anisotropic tetragonal L1₀ phase; annealing; coercivity; crystal structure; grain size; magnetic properties; microstructure; multilayer; nanocomposite granular thin film; Anisotropic magnetoresistance; Annealing; Furnaces; Grain size; Magnetic anisotropy; Magnetic films; Magnetic multilayers; Magnetic properties; Perpendicular magnetic anisotropy; Sputtering;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.950821

Filename

950821