Reduction of ordering temperature of an FePt-ordered alloy by addition of Cu

Abstract

We have found that the addition of Cu to an FePt alloy film is an effective approach for reducing the ordering temperature of FePt. The coercivity of the FePtCu film is around 5 kOe after annealing at 300 °C, whereas that of FePt shows several hundred Oe. In the FePtCu film annealed at 700 °C, the coercivity is almost the same as for the FePt films. Therefore, the FePtCu film displays a hard-magnetic property similar to that of the FePt film. The results of x-ray diffraction indicate that a ternary FePtCu alloy is formed. Thus, the formation of the ternary FePtCu alloy is considered to play an important role in reducing the ordering temperature.

Continuously graded anisotropy in single (Fe53Pt47)100−xCux films

“…21 Note that the ͑111͒ peak is shifted to angles higher than that of fully ordered FePt ͑41.08°͒ due to the Cu dopant which has been shown to decrease the c lattice parameter. 19 While an increase in L1 0 order is found with increasing annealing temperature, how the structural A1-L1 0 ordering gradient ͑and thus the magnetic K u gradient͒ is manifested through the thickness of the film is not readily accessible from the XRD measurements.…”

“…[14][15][16][17][18] In this letter, we report on a simple approach to fabricate continuously graded-K u single films based on the strong dependence of the A1 ͑low K u ͒ → L1 0 ͑high K u ͒ ordering temperature on the Cu content in ͑Fe 53 Pt 47 ͒ 100−x Cu x ͑x =0-30͒ films. 19 First, a compositional gradient is achieved by varying the Cu concentration from Cu-rich ͑Fe 53 Pt 47 ͒ 70 Cu 30 at the bottom to Cu-free Fe 53 Pt 47 at the top during film deposition, as schematically represented in Fig. 1 ͑left panel͒.…”

Phase transformation in sputter-deposited PdMn and PdPtMn thin films

“…Alloying in PtMn of Pd may affect the phase transformation temperature. [17][18][19] For example, favorable kinetics for the transformation in PtMn thin films were only found above 260°C ͑Ref. 8͒ and a postdeposition annealing step at 230°C for 1 h was reported for PdPtMn thin films.…”

Perpendicular magnetic anisotropy in chemically disordered FePd–FeV(100) alloy thin films

“…6͔͒, a fact that can be a drawback for the production of technological devices. In this scope alternative methods used in recent years to obtain PMA in alloys grown at a lower temperature and with a smaller chemical ordering degree include the addition of third elements, 7 artificial multilayering, 8 ion irradiation, 9 monoatomic layer control, 10 compositional changes, 11 and selection of buffer layer nature. 12 This last method, a buffer layer between the substrate and the binary alloy, is generally used to increase the flatness of the initial growing surface and to decrease the existent lattice mismatch, and it has been demonstrated that the nature, 5,10-17 thickness, 5 and deposition temperature 13 of the buffer layer affect strongly the ordering degree of the binary alloy.…”