科研之友
微信
新浪微博
Facebook
分享链接
摘要
We report on the evolution of uncapped Fe70Ga30 layers deposited by sputtering and post-growth annealed in oxygen atmosphere in a temperature range from 500 degrees C to 800 degrees 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 degrees C whereas a further increase of the temperature up to 800 degrees C promotes the transformation to Fe2O3. We have observed by x-ray absorption fine structure the partial oxidation of Ga and the formation of Ga aggregates at 600 degrees 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 Fe2O3. 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 degrees 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 Fe2O3 is detected.
- 出版日期2017-8-5
