Preparation of metastable bcc permal1oy epitaxial thin films on GaAs(011)_(B3 ) single-crystal substrates

摘要

Permalloy (Py) single-crystal films with bcc structure were obtained on GaAs(011 )_(B3 )single-crystal substrates by ultra high vacuum rf magnetron sputtering. The film growth and the detailed film structures were investigated by refection high energy electron diffraction and pole figure X-ray diffraction. bcc-Py films epitaxially grow on the substrates in the orientation relationship of Py(011 )[011 ]_(bcc) || GaAs(011 )[011 ]_(B3). The lattice constant of bcc-Py film is determined to be a = 0.291 nm. With increasing the film thickness, parts of the bcc crystal transform into more stable fee structure by atomic displacement parallel to the bcc{011} dose-packed planes. The resulting film thus consists of a mixture of bcc and fee crystals. The phase transformation mechanism is discussed based on the experimental results. The in-plane magnetization properties reflecting the magnetocrystalline anisotropy of bcc-Py crystal are observed for the Py films grown on GaAs(011)_(B3 )substrates.