Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8032562 | Thin Solid Films | 2018 | 10 Pages |
Abstract
Influence of heat treatment atmosphere on magnetic properties of post-annealed [FePt(15â¯nm)/Au(7.5â¯nm)/FePt(15â¯nm)]2x thin films was investigated. Thin films were deposited by dc magnetron sputtering at room temperature onto SiO2(100â¯nm)/Si(100) substrates and post-annealed in a temperature range of 500â¯Â°C-800â¯Â°C for 30â¯s in flowing Ar and Arâ¯+â¯H2 (3â¯vol%) atmospheres. It was shown that hydrogen addition into annealing atmosphere allows to achieve high value of coercivity ~1671.1â¯kA/m after annealing at 600â¯Â°C. Such coercivity could be reached by heat treatment in pure Ar just after annealing at 700â¯Â°C. This effect could be related to acceleration of Au grain boundary diffusion into L10-FePt phase. Such acceleration could be possible due to two reasons: hydrogen incorporation into Au crystal lattice, leading to interatomic bounds break and point defects formation; and hydrogen segregation at most defective areas, leading to cohesive energy decrease and upraise of significant stresses. As a result, nonmagnetic grid in grain boundaries of ferromagnetic material was formed at temperature lower by 100â¯Â°C.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
A.K. Orlov, O.O. Zhabynska, I.A. Vladymyrskyi, S.M. Voloshko, S.I. Sidorenko, K. Kato, T. Ishikawa,