Effect of Cr 100- xTi x ( x = 0-19 at.%) alloy underlayers on the high coercivity of FePt thin film below the substrate temperature of 250 °C
Abstract
The effect of Cr 100- xTi x underlayer on orderd- L1 0 FePt films was investigated. A low-temperature ordering of FePt films could be attained through changing the Ti content of Cr 100- xTi x underlayer. The ordering temperature of the 30 nm FePt film grown on 20 nm Cr 90Ti 10 underlayer was reduced to 250 °C which is practical manufacture process temperature. An in-plane coercivity was very high to 6000 Oe and a ratio of remnant magnetization ( Mr) to saturation magnetization ( Ms) was as large as 0.85. This result indicates that the coercivity obtained at 250 °C by the effect of CrTi underlayer is significantly higher than those obtained at 250-275 °C by the effect of underlayers in other conventional studies. The prominent improvement of the magnetic properties of ordered FePt thin films at low temperature of 250 °C could be understood with considering the strain-induced ordering phase transformation associated with lattice mismatch between Cr underlayer and FePt magnetic layer due to an addition of Ti content.
- Publication:
-
Applied Surface Science
- Pub Date:
- October 2011
- DOI:
- 10.1016/j.apsusc.2011.08.131
- Bibcode:
- 2011ApSS..258..404L