کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1798046 1524803 2016 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thickness dependent ferromagnetism in thermally decomposed NiO thin films
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Thickness dependent ferromagnetism in thermally decomposed NiO thin films
چکیده انگلیسی


• Preparation of highly strained single layer NiO films with different thicknesses.
• Study the effects of annealing under different environments on crystal structure.
• Understanding the origin of thickness dependent thermal decomposition reaction.
• Investigate the role of thermal decomposition reaction on the magnetic properties.
• Study the interaction between NiO and Ni phases on the exchange bias mechanism.

We report the effects of film thickness, annealing temperature and annealing environments on thermal decomposition behavior and resulting magnetic properties of NiO (t=50–300 nm) thin films. All the NiO films were prepared directly on thermally oxidized Si at ambient temperature using magnetron sputtering technique and post annealed at different temperatures (TA) under vacuum and oxygen atmospheres. As-deposited films exhibit face centered cubic structure with large lattice constant due to strain induced during sputtering process. With increasing TA, the lattice constant decreases due to the release of strain and thickness dependent thermal decomposition reaction of NiO into Ni has been observed for the NiO films annealed at 500 °C under vacuum condition. As a result, the antiferromagnetic nature of the as-deposited NiO films transforms into ferromagnetic one with dominant thickness dependent ferromagnetic behavior at room temperature. In addition, the existence of both Ni and NiO phases in the annealed NiO films shows noticeable exchange bias under field cooling condition. The behavior of thermal decomposition was not observed for the NiO films annealed under oxygen condition which results in no detectable change in the magnetic properties. The observed results are discussed on the basis of thickness dependent thermal decomposition in NiO films with increasing TA and changing annealing conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetism and Magnetic Materials - Volume 418, 15 November 2016, Pages 86–91
نویسندگان
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