Kim, Kyung-Ho Kim, Hyung-jun Ahn, Jae-Pyung Lee, Seung-Cheol Won, Sung Ok Choi, Jun Woo Chang, Joonyeon 2024-01-20T15:35:04Z 2024-01-20T15:35:04Z 2021-09-05 2011-12-01 0021-8979 https://pubs.kist.re.kr/handle/201004/129725 Microstructure and the corresponding magnetic property of epitaxial MgO and subsequent Fe layers in situ grown on GaAs(001) substrates are investigated as a function of the epitaxial layer thicknesses. It is found that the MgO layers retain a 1.6 nm thick Mg-rich amorphous layer at the initial stage of the MgO growths regardless of its total thickness. Systematic x-ray diffraction analysis reveals that the MgO layers are under in-plane compressive strain which is partially relaxed as the total MgO thickness increases from 4 to 20 nm. The misfit strain within the MgO layers results in three-dimensional Fe islands forming at lower thickness with two different zone axis of [010] or [1 (1) over bar0]. Furthermore, the islands coalesce as the nominal thickness increases, resulting in serpentine-shaped Fe islands. Finally, it completely covers the underlying MgO layers, forming an epitaxial Fe layer at the nominal thickness higher than 10 nm. The three-dimensional Fe islands at the initial stage show superparamagnetism, which becomes ferromagnetic as the Fe forms a two-dimensional layer. (C) 2011 American Institute of Physics. [doi:10.1063/1.3665887] English AMER INST PHYSICS PULSED-LASER DEPOSITION MOLECULAR-BEAM EPITAXY THIN-FILMS FE/MGO HETEROSTRUCTURES GAAS(001) MGO(001) SI(001) Epitaxial growth of Fe and MgO layers on GaAs (001): Microstructure and magnetic property Article 10.1063/1.3665887 1 JOURNAL OF APPLIED PHYSICS, v.110, no.11 JOURNAL OF APPLIED PHYSICS 110 11 scie scopus 000298254800174 2-s2.0-84859311050 Physics, Applied Physics Article PULSED-LASER DEPOSITION MOLECULAR-BEAM EPITAXY THIN-FILMS FE/MGO HETEROSTRUCTURES GAAS(001) MGO(001) SI(001) GaAs MgO Fe Strain Microstructure Magnetics