Orientation and Magnetic Properties of FePt and CoPt Films Grown on MgO(110) Single-Crystal Substrate by Electron-Beam Coevaporation

Published

October 12, 2021

Author(s)

M-H Yu, Hiroyuki Ohguchi, Antonio Zambano, Ichiro Takeuchi, J P. Liu, Daniel Josell, Leonid A. Bendersky

Abstract

We have studied the orientation and magnetic properties of FePt and CoPt films deposited by electron-beam co-evaporation on MgO(110) single-crystal substrates at different substrate temperatures between 500 and 700 degrees C. We observed that the long range chemical ordering of L1_subscript 0 phase occurred over the entire range of substrate temperatures in FePt films and at 600 degrees C and higher in CoPt films. At 600 degrees C, the growth of FePt and CoPt yields nearly single orientation epitaxial films: FePt(110)[001}//MgO(110)[001]//MgO(110)[001]. Large in-plane magnetocrystalline anisotropy was also observed in both FePt(110) and CoPt(110) films. X-ray diffraction patterns and magnetization loops of the FePt(110) and CoPt(110) films also revealed the existence of two kinds of minor phases: chemically disordered (fcc) phase, and [100] and [010] variants of the chemically ordered L1-subscript 0 phases with the tetragonal c axis inclined at 45 degrees to the film plane. The FePt(110) and CoPt(110) films grown at 600 degrees C exhibited the largest exchange-coupling interaction between the disordered soft phase and the ordered hard phases. The [100] and [010] variants of the ordered L1_subscript 0 phases are responsible for the noticeable remanence and corecivity observed along the in-plane and out-of-plane hard axes. In the FePt films, we found that the use of clamps to fix the substrate to the heater plate, instead of indium, can induce the growth of additional L1_subscript 0 phase with c axis along the film normal.

Citation

IEEE Transactions on Magnetics

Pub Type

Journals

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Citation

Yu, M. , Ohguchi, H. , Zambano, A. , Takeuchi, I. , Liu, J. , Josell, D. and Bendersky, L. (2021), Orientation and Magnetic Properties of FePt and CoPt Films Grown on MgO(110) Single-Crystal Substrate by Electron-Beam Coevaporation, IEEE Transactions on Magnetics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=853490 (Accessed January 26, 2025)