2026-06-28T20:24:29Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/180602023-08-27T23:27:19Zcom_20.500.14352_14col_20.500.14352_15

Morphological, structural and magnetic evolution of sputtered Fe70Ga30 thin films upon annealing in oxygen atmosphere Bisero, D. Fin, S. Ranchal Sánchez, Rocío We report on the evolution of uncapped Fe_(70)Ga_(30) layers deposited by sputtering and post-growth annealed in oxygen atmosphere in a temperature range from 500 °C to 800 °C. We have investigated the morphology, structure and magnetic properties of films with a thickness of 200 nm deposited on Mo buffer layers on glass substrates. X-ray diffractometry shows a decrease of the lattice parameter up to 600 °C whereas a further increase of the temperature up to 800 °C promotes the transformation to Fe_2O_3. We have observed by x-ray absorption fine structure the partial oxidation of Ga and the formation of Ga aggregates at 600 °C. These aggregates form Ga-rich bubbles that can be observed on the sample surface from which Ga evaporates leaving a Ga-poor layer that is later oxidized into Fe_2O_3. The thermal treatment on oxygen atmosphere has also a clear impact on the magnetic properties of the layers. The uniaxial in-plane magnetic anisotropy of the as-grown film evolves to magnetic isotropy when annealed at 600 °C probably due to the segregation and formation of Ga-rich areas. After Ga evaporates from the sample, Fe is fully oxidized and only a weak ferromagnetism related to Fe_2O_3 is detected. 2023-06-17T22:05:57Z 2023-06-17T22:05:57Z 2023-06-17T22:05:57Z 2017 journal article https://hdl.handle.net/20.500.14352/18060 0925-8388 10.1016/j.jallcom.2017.04.158 eng MAT2015-66888-C3-3-R open access Elsevier Science SA