Effect of additional Au layer on ordering processes in FePt alloy films on and without substrates during high-temperature annealing

• Published in: Applied nanoscience Vol. 13; no. 7; pp. 5291 - 5302
• Main Authors: Makushko, P. V., Shamis, M. N., Kotenko, I. E., Schmidt, N. Y., Verbytska, T. I., Makogon, Iu. M.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.07.2023; Springer Nature B.V
• Subjects: Annealing; Chemistry and Materials Science; Coercivity; Ferrous alloys; Grain boundaries; High temperature; Intermetallic compounds; Iron compounds; Magnetic properties; Materials Science; Membrane Biology; Nanochemistry; Nanotechnology; Nanotechnology and Microengineering; Original Article; Platinum compounds; Residual stress; Silicon dioxide; Silicon substrates; Thin films; Magnetic recording media; 1; FePt; Ordered phase; Coercivity; Stress
• ISSN: 2190-5509; 2190-5517
• DOI: 10.1007/s13204-022-02754-6

The effect of the location of an additional Au layer (top, intermediate, and bottom) on the residual stresses, structure, the transformation of the disordered A 1 phase into the ordered L 1 0 FePt phase, and magnetic properties of layered FePt(15 nm)-Au films on SiO 2 (100 nm)/Si(001) substrate is investigated. The ordering processes in the films separated from the substrates during in situ annealing are studied as well. It is shown that the level of mechanical stresses depends on the Au layer location and the number of interfaces in FePt–Au films. Both films (on the substrate and separated from it) with an intermediate Au layer had the lowest temperature of the beginning of L 1 0 phase formation. During annealing, diffusion of Au and its redistribution along the grain boundaries of the L 1 0 FePt phase occur. An increase in the Au concentration along the grain boundaries reduces the exchange interaction between them and increases the coercivity of the FePt/Au and Au/FePt films.