Effects of rapid thermal annealing on nanostructure, texture and magnetic properties of granular FePt:Ag films for perpendicular recording (invited)

Abstract

We report effects of rapid thermal annealing on nanostructure, texture, and magnetic properties of granular FePt:Ag films. It was found that the orientations of FePt grains were dependent strongly on the as-deposited multilayer structure and the annealing processes. Through the control of the annealing processes, ͑001͒ textured L1 0 granular FePt:Ag films were obtained. Magnetic measurements revealed that saturation magnetization M s , perpendicular coercivity H c , and remanence ratio M r /M s , were also dependent on the annealing temperature, annealing time and Ag content. Perpendicular H c values increased from 1.5 to 15 kOe when the annealing temperature changed from 400 to 600°C for 600 s. Perpendicular H c values remained about 11 kOe when the annealing time changed from 5 to 600 s. The effect of Ag content on magnetic properties is reported.

Magnetism of L1 compounds with the composition MT (M=Rh, Pd, Pt, Ir and T=Mn, Fe, Co, Ni)

“…[1][2][3][4][5][6][7] These compounds are of fundamental interest for their high uniaxial anisotropy to about 10 7 MJ/m 3 , which results from their natural superlattice structure, and CoPt was the first true permanent-magnet alloy. In addition, L1 0 nanoclusters have high potential as cluster-assembled granular films for 1 Tb/in.…”

Fabrication of nonepitaxially grown double-layered FePt:C/FeCoNi thin films for perpendicular recording

“…4 -6 The fabrication conditions, annealing processes, and magnetic properties of these ͑001͒ textured films also have been investigated systematically. [5][6][7][8][9] For practical applications, nonepitaxially grown L1 0 nanocomposite FePtbased thin films are advantageous because of the ease of growth. In this letter, we report the design and fabrication of nonepitaxially grown ͑001͒ textured L1 0 nanocomposite FePt:C thin films with a soft-magnetic underlayer ͑SUL͒.…”

Assembly of high-anisotropy L10 FePt nanocomposite films

“…Recently, non-epitaxially grown, highly (0 0 1)-textured L1 0 FePt [9,10] and FePt based fi lms [18] have been obtained by using multilayer deposition plus post annealing. It is found that orientations of FePt grains are affected by many preparation parameters, such as initial as-deposited fi lm structure, composition, annealing time and so on [19,20]. Fig.…”

“…With increasing Ag content the hysteresis-loop slope and the correlation length decrease, whereas the coercivity increases. The Ag increases the separation between the particles, thereby effectively exchange-decoupling the grains [19].…”