Journal of the Magnetics Society of Japan
Online ISSN : 1882-2932
Print ISSN : 1882-2924
Thin Films, Fine Particles, Multilayers, and Superlattices
Structural Characterization of Co Thin Film with bcc-Based A2 Structure Epitaxially Grown on GaAs(100) Single-Crystal Substrate
Shigeyuki MinakawaMitsuru OhtakeDaisuke SuzukiNobuyuki InabaMasaaki Futamoto
ジャーナル オープンアクセス

2014 年 38 巻 5 号 p. 185-193


  Co films are prepared on GaAs(100) single-crystal substrates at temperatures ranging between room temperature and 600 °C by varying the thickness from 1 to 40 nm. The growth behavior and the detailed structure are investigated by reflection high-energy electron diffraction and X-ray diffraction. (100)-oriented Co single-crystals with bcc-based A2 structure are formed in early stages of film growth at temperatures lower than 200 °C, where the bcc-based A2 structure is stabilized through hetero-epitaxial growth. With increasing the thickness up to 2 nm, the A2 structure starts to transform into more stable hcp-based A3 structure through atomic displacements from A2{110} to A3(0001) close-packed plane. The films thicker than 2 nm thus involve six types of A3 crystal. As the substrate temperature increases up to 400 °C, large amounts of Ga and As atoms diffuse from the substrate into the film, and Co-Ga and Co-Ga-As alloy crystals with bcc-based B2 and L21 structures are formed.

© 2014 The Magnetics Society of Japan