Broad UHF ferromagnetic resonance of iron rich-aluminum pulsed laser deposited thin films
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- 作者：V. Madurga ; J. Vergara ; C. Favieres
- 关键词：Amorphous metals ; Metallic glasses ; Transition metals ; Composition ; Films and coatings ; Laser deposition ; Magnetic properties ; Nanoparticles ; Colloids and quantum structures ; Nanocrystals ; Resonance methods
- 刊名：Journal of Non-Crystalline Solids
- 出版年：2008
- 出版时间：1 December 2008
- 年：2008
- 卷：354
- 期：47-51
- 页码：5198-5200
- 全文大小：738 K
文摘
The magnetic susceptibility of Fe–Al off-normal pulsed laser deposited thin films was measured at ultra high frequencies, UHF. Different Fe1−x–Alx films from pure Fe to x = 0.2 Al were prepared. The films were ≈40 nm thick and non-crystalline peaks were detected by the X-ray diffractometry studies. The magnetization of the films remained between 2.0 and 1.8 T for composition less than or equal to 20 % Al. A magnetic anisotropy, from Hk ≈ 18 Oe for pure Fe to Hk ≈ 130 Oe for 20 % Al was measured. These samples exhibited a well-defined ferromagnetic resonance at frequencies between ≈2.0 GHz and 3.8 GHz depending on composition. The broad resonance peaks had a width, at half maximum, wh, in the interval from 2.5 GHz to 4.0 GHz depending on Al content. After fitting the magnetic hysteresis loops using a simple distribution of anisotropy values, we used the Landau–Lifshitz–Gilbert equation to fit the UHF magnetic susceptibility. From this last fit we obtained a high damping coefficient value (≈4 times higher than that corresponding to Co or CoFe films), explaining this broad ferromagnetic resonance of these Fe1−x–Alx films.