Effect of Copper on the Formation of Ordered L10(FePt) Phase in Nanosized Fe50Pt50/Cu/Fe50Pt50 Films on SiO2/Si (001) Substrates

• Published in: Powder metallurgy and metal ceramics 2016-05, Vol.55 (1-2), p.109-113
• Main Authors: Verbitskaya, T. I., Figurnaya, E. V., Verbitskaya, M. Yu, Vladymyrskyi, I. A., Sidorenko, S. I., Pavlova, E. P., Makogon, Yu. N.
• Format: Article
• Language: English
• Subjects: Annealing; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Coercivity; Composites; Copper; Diffusion layers; Glass; Intermetallic compounds; Iron compounds; Magnetic properties; Materials Science; Measurement methods; Metallic Materials; Natural Materials; Phase transitions; Platinum compounds; Silicon dioxide; Silicon substrates; Thickness; X-ray diffraction
• ISSN: 1068-1302; 1573-9066
• DOI: 10.1007/s11106-016-9785-0

The effect from thickness of an intermediate copper layer in nanosized Fe 50 Pt 50 (15 nm)/Cu (x)/Fe 50 Pt 50 (15 nm) (x = 7.5, 15, and 30 nm) composite films on SiO 2 (100 nm)/Si(001) substrates on the diffusion-controlled phase formation processes—transformation of the disordered magnetically soft A1(FePt) phase into the ordered magnetically hard L1 0 (FePt) phase during annealing in vacuum—is studied by physical materials science methods: X-ray diffraction and measurement of magnetic properties. The A1(FePt) phase forms in all films during deposition. Annealing in vacuum in the temperature range 300–900°C is accompanied by thermally activated diffusion processes between the Cu and FePt layers. When thickness of the intermediate Cu layer increases from 7.5 nm up to 15 nm, the onset temperature of A1(FePt) → L1 0 (FePt) phase transformation raises by 100°C, i.e., to 800°C. Simultaneously, the coercivity in films decreases since Cu dissolves in the FePt lattice.