Characterization of metastable crystal structure for Co-Pt alloy thin film by x-ray diffraction
- Faculty of Science and Engineering, Chuo University, Bunkyo-ku, Tokyo 112-8551 (Japan)
Co{sub 50}Pt{sub 50} and Co{sub 75}Pt{sub 25} (at. %) alloy epitaxial films with the close-packed plane parallel to the substrate surface are prepared on MgO(111) substrates with and without Ti(0001) underlayer at 300 °C. The structural properties are investigated by using a combination of out-of-plane, in-plane, and pole-figure x-ray diffractions. The crystal structure is determined by taking into account the order degree and the atomic stacking sequence of close-packed plane. Formation of a metastable ordered fcc-based L1{sub 1}-CoPt phase is recognized for the Co{sub 50}Pt{sub 50} film deposited on MgO(111) substrate, whereas a metastable ordered hcp-based B{sub h}-CoPt phase is involved in the Co{sub 50}Pt{sub 50} film deposited on Ti(0001) underlayer in addition to an L1{sub 1}-CoPt phase. The Co{sub 75}Pt{sub 25} film deposited on MgO(111) consists of a mixture of ordered hcp-based phases of B{sub h}-CoPt and D0{sub 19}-Co{sub 3}Pt. An accurate order degree is calculated by comparing the out-of-plane superlattice and fundamental reflection data. A simplified method for estimating the order degree, where there are only two kinds of parameter: intensity ratio of superlattice to fundamental reflection and out-of-plane lattice spacing, is also proposed. The order degree estimated by the simplified method agrees in a small error less than a few percentages with the accurate value.
- OSTI ID:
- 22273791
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 17 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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