Fe3O4 thin films epitaxially growth model on TiO2-terminated SrTiO3(100)

• Published in: Micro and nanostructures (2022) Vol. 167; p. 107183
• Main Authors: Cheng, Bin, Liu, Xing, Hu, Jifan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2022
• Subjects: Epitaxy; Hetero-interface; Maghemite; Magnetite; Polar; Spintronic; Magnetite; Spintronic; Hetero-interface; Polar; Epitaxy; Maghemite
• ISSN: 0749-6036; 2773-0123; 1096-3677; 2773-0123
• DOI: 10.1016/j.spmi.2022.107183

The advanced interface of Fe3O4/SrTiO3, popular in spintronic, has attracted considerable attention. Some experiments have given controversial results on the structure at the Fe3O4/SrTiO3(100) interface. One opinion suggests the formation of interfacial antiferromagnetic FeO layers, while another opinion suggests that are γ-Fe2O3 layers. Here, we propose a theoretical model that what kind of iron oxide stacking sequence forming on the substrate depends on the substrate termination charge. We give a tentative and easy-to-understand growth model for epitaxy, which agrees with the opinion of γ-Fe2O3 layers formation at the Fe3O4/SrTiO3(100) interface. This theoretical model agrees well with the experimental curve and gives a prediction for the different Fe ions concentration depending on thickness. The calculation results of the Fe ions concentration adjacent to the substrate surface show that there are almost no B-site Fe ions at the interface. It indicates that there are unusual electric and magnetic properties at interface. Our growth model illustrates that the possible magnetically dead layer at the interface is responsible for the decrease of the magnetization in the thin films. •This growth mode give credit to the results of interfacial ferrimagnetic γ-Fe2O3 layer in Fe3O4/SrTiO3(100).•The model curve agrees with the experimental curve, gives prediction for the Fe ions concentration depending on thickness.•There are almost no B-site Fe at interface. There exists possible magnetically dead layer at the interface.•The growth mode and the oxidation level are determined by the TiO2-termination charge.•The magnetite film grown on SrTiO3(001) exhibiting vertical compressive and lateral tensile strain has been explained.