Soft magnetic properties of FeAl- and FeGa-based thin films for high frequency application
| Autor: | Ming-yong Jian, 簡明勇 |
|---|---|
| Rok vydání: | 2009 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 97 The ferromagnetic resonance frequency (fFMR) of the magnetic thin films is proportional to the square root of the saturation magnetization (4πMs) and magnetic anisotropy field (Hk). To select a starting material having high 4πMs and also to induce high Hk in the film are two crucial points for it to exhibit high fFMR. In this study, FeAl-based alloy was firstly used to deposit thin film due to its low-cost, high saturation magnetization and large magnetostriction. For Fe81Al19 thin film, the larger magnetic anisotropy field of about 165 Oe can be achieved, while the optimal magnetic properties of 4πMs=12.8 kG, Hce=66.5 Oe, Hch=15.7 Oe, Hk=56 Oe, ρ=357 μΩ-cm, fFMR, cal. =2.4 GHz, and permeability of 250 were achieved with an oblique sputtering angle of δ=15o. Meanwhile, since FeGa alloy has higher magnetostriction constant than that of the FeAl alloy, we also studied the magnetic properties of the Fe81Al19-xGax (x=4 and 8) thin films with different oblique angles. As a result, with increasing Ga content, the Hk increased from Hk=165 Oe for Fe81Al19 to Hk=221 Oe for Fe81Al11Ga8 with δ=30o. To further reduce the coercivity of the film, boron element was adopted to substitute for aluminum for depositing Fe81Al10B9 films. The optimum properties of 4πMs=12.9 kG, Hk=55 Oe, Hce=29.1 Oe, Hch=8.1 Oe, ρ=345 µΩ-cm, fFMR of 2.4 GHz, and permeability of 300 were achieved in 110 nm Fe81Al10B9 film with δ=25o. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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