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Impedance of nanometer thickness ferromagnetic Co40Fe40B20 films.

Jen SU, Chou TY, Lo CK - Nanoscale Res Lett (2011)

Bottom Line: In the h//w case, IM spectra show QFMR-K at F0 and FMR-W at Fn.We find that f0 and F0 are shifted from fFMRK, respectively, and fn = Fn.The in-plane spin-wave resonances are responsible for those relative shifts.PACS No. 76.50.+q; 84.37.+q; 75.70.-i.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physics, Academia Sinica, Taipei, Taiwan, 11529, Republic of China. physjen@gate.sinica.edu.tw.

ABSTRACT
Nanocrystalline Co40Fe40B20 films, with film thickness tf = 100 nm, were deposited on glass substrates by the magnetron sputtering method at room temperature. During the film deposition period, a dc magnetic field, h = 40 Oe, was applied to introduce an easy axis for each film sample: one with h//L and the other with h//w, where L and w are the length and width of the film. Ferromagnetic resonance (FMR), ultrahigh frequency impedance (IM), dc electrical resistivity (ρ), and magnetic hysteresis loops (MHL) of these films were studied. From the MHL and r measurements, we obtain saturation magnetization 4πMs = 15.5 kG, anisotropy field Hk = 0.031 kG, and r = 168 mW.cm. From FMR, we can determine the Kittel mode ferromagnetic resonance (FMR-K) frequency fFMRK = 1,963 MHz. In the h//L case, IM spectra show the quasi-Kittel-mode ferromagnetic resonance (QFMR-K) at f0 and the Walker-mode ferromagnetic resonance (FMR-W) at fn, where n = 1, 2, 3, and 4. In the h//w case, IM spectra show QFMR-K at F0 and FMR-W at Fn. We find that f0 and F0 are shifted from fFMRK, respectively, and fn = Fn. The in-plane spin-wave resonances are responsible for those relative shifts.PACS No. 76.50.+q; 84.37.+q; 75.70.-i.

No MeSH data available.


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Two Co40Fe40B20 film samples. L is the length and w the width. iac is the ac current sent through each sample.  is the saturation magnetization and  is the deposition field.  and  are the in-plane spin-wave wave vectors. (a) The //L case and (b) the //w case.
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Figure 1: Two Co40Fe40B20 film samples. L is the length and w the width. iac is the ac current sent through each sample. is the saturation magnetization and is the deposition field. and are the in-plane spin-wave wave vectors. (a) The //L case and (b) the //w case.

Mentions: The composition of the film sample in this test was Co40Fe40B20. We used magnetron sputtering technique to deposit the film on a glass substrate at room temperature. The film thickness tf, as mentioned before, was 100 nm. During the deposition period, an external dc field, h ≅ 40 Oe, was applied to define the easy axis, as shown in Figure 1, for each nanometer thick sample. In Figure 1, we have length, L = 10.0 mm, and width, w = 500 μm, in case (a) h//L, and in case (b) h//w. is the saturation magnetization of each film. In addition, the nanocrystalline grain structures in our CoFeB films were confirmed from their transmission electron microscope photos.


Impedance of nanometer thickness ferromagnetic Co40Fe40B20 films.

Jen SU, Chou TY, Lo CK - Nanoscale Res Lett (2011)

Two Co40Fe40B20 film samples. L is the length and w the width. iac is the ac current sent through each sample.  is the saturation magnetization and  is the deposition field.  and  are the in-plane spin-wave wave vectors. (a) The //L case and (b) the //w case.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211980&req=5

Figure 1: Two Co40Fe40B20 film samples. L is the length and w the width. iac is the ac current sent through each sample. is the saturation magnetization and is the deposition field. and are the in-plane spin-wave wave vectors. (a) The //L case and (b) the //w case.
Mentions: The composition of the film sample in this test was Co40Fe40B20. We used magnetron sputtering technique to deposit the film on a glass substrate at room temperature. The film thickness tf, as mentioned before, was 100 nm. During the deposition period, an external dc field, h ≅ 40 Oe, was applied to define the easy axis, as shown in Figure 1, for each nanometer thick sample. In Figure 1, we have length, L = 10.0 mm, and width, w = 500 μm, in case (a) h//L, and in case (b) h//w. is the saturation magnetization of each film. In addition, the nanocrystalline grain structures in our CoFeB films were confirmed from their transmission electron microscope photos.

Bottom Line: In the h//w case, IM spectra show QFMR-K at F0 and FMR-W at Fn.We find that f0 and F0 are shifted from fFMRK, respectively, and fn = Fn.The in-plane spin-wave resonances are responsible for those relative shifts.PACS No. 76.50.+q; 84.37.+q; 75.70.-i.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physics, Academia Sinica, Taipei, Taiwan, 11529, Republic of China. physjen@gate.sinica.edu.tw.

ABSTRACT
Nanocrystalline Co40Fe40B20 films, with film thickness tf = 100 nm, were deposited on glass substrates by the magnetron sputtering method at room temperature. During the film deposition period, a dc magnetic field, h = 40 Oe, was applied to introduce an easy axis for each film sample: one with h//L and the other with h//w, where L and w are the length and width of the film. Ferromagnetic resonance (FMR), ultrahigh frequency impedance (IM), dc electrical resistivity (ρ), and magnetic hysteresis loops (MHL) of these films were studied. From the MHL and r measurements, we obtain saturation magnetization 4πMs = 15.5 kG, anisotropy field Hk = 0.031 kG, and r = 168 mW.cm. From FMR, we can determine the Kittel mode ferromagnetic resonance (FMR-K) frequency fFMRK = 1,963 MHz. In the h//L case, IM spectra show the quasi-Kittel-mode ferromagnetic resonance (QFMR-K) at f0 and the Walker-mode ferromagnetic resonance (FMR-W) at fn, where n = 1, 2, 3, and 4. In the h//w case, IM spectra show QFMR-K at F0 and FMR-W at Fn. We find that f0 and F0 are shifted from fFMRK, respectively, and fn = Fn. The in-plane spin-wave resonances are responsible for those relative shifts.PACS No. 76.50.+q; 84.37.+q; 75.70.-i.

No MeSH data available.


Related in: MedlinePlus