Electrodynamic theory of ferromagnetic resonance and its applications in precise measurements of ferromagnetic linewidth, permeability tensor and saturation magnetization

New values have been obtained for the magnetoelastic coefficients h 3 and h 4 of nickel at room temperature from ferromagnetic resonance experiments on (100) single crystal nickel films. The ratios of h 3 / h 1 and h 4 / h 1 are found to be 0.091 ± 0.007 and 0.153 ± 0.015 respectively which give h 3 = (- 8.5 ± 0.7) x 10 -6 and h 4 = (- 14.3 ± 1.4) x 10 -6 if the Lee & Asgar value of h 3 is used (- 94 x 10 -6 ). The magnetocrystalline anisotropy constant K 1 , the saturation magnetization M and the spectroscopic splitting factor g have been measured also. It is found that K 1 = ( - 5.4 ± 0.3) x 10 4 erg/cm 3 and that g = 2.161 ± 0.009 in agreement with published data on bulk samples but that the value of M is found to be higher than the bulk value by 1.6%. The discrepancies between the values of h 3 , h 4 and M as reported here and the bulk values are discussed. The theory of feromagnetic resonance has been extended to cover the five-constant representation of magnetostriction and to the K 3 anisotropy term. The effect of the g factor having cubic anisotropy on the resonance conditions has been calculated.

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FeCoB Films with Large Saturation Magnetization and High Magnetic Anisotropy Field to Attain High Ferromagnetic Resonance Frequency

Journal of Magnetics ◽

10.4283/jmag.2013.18.2.155 ◽

2013 ◽

Vol 18 (2) ◽

pp. 155-158 ◽

Cited By ~ 1

Author(s):

Shigeki Nakagawa ◽

Ken-Ichiro Hirata

Keyword(s):

Magnetic Anisotropy ◽

Resonance Frequency ◽

Saturation Magnetization ◽

Ferromagnetic Resonance ◽

Anisotropy Field ◽

Ferromagnetic Resonance Frequency

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Магнитная анизотропия многослойных гетероструктур [(Co-=SUB=-41-=/SUB=-Fe-=SUB=-39-=/SUB=-B-=SUB=-20-=/SUB=-)-=SUB=-x-=/SUB=-(SiO-=SUB=-2-=/SUB=-)-=SUB=-100-x-=/SUB=-/Bi-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-]-=SUB=-47-=/SUB=-

Физика твердого тела ◽

10.21883/ftt.2019.02.47124.235 ◽

2019 ◽

Vol 61 (2) ◽

pp. 266

Author(s):

А.И. Безверхний ◽

А.Д. Таланцев ◽

Ю.Е. Калинин ◽

А.В. Ситников ◽

В.A. Никитенко ◽

...

Keyword(s):

Saturation Magnetization ◽

Ferromagnetic Resonance ◽

Magnetic Moment ◽

Average Diameter ◽

Anisotropy Constant ◽

The Relationship

AbstractMagnetic anisotropy values are obtained for [(Co_41Fe_39B_20)_ x (SiO_2)_100 – _ x /Bi_2Te_3]_47 heterostructures consisting of SiO_2 alternating layers, CoFeB nanoparticles distributed in them, and Bi_2Te_3 layers with ferromagnetic resonance and magnetometry. The heterostructures have anisotropy of ~10^6 erg/cm^3, which orients the magnetic moment in films plane. The films are not solid, but they disintegrate into CoFeB nanoparticles with an average diameter of 5 nm during deposition, which corresponds to the blocking magnetization temperature of ~30 K during their saturation magnetization of M _ S = 720 emu/cm^3. The relationship between anisotropy constant and thickness of the layers of the heterostructures is nonmonotonic due to competition between surface and bulk anisotropies of the ferromagnetic granules, which the films are made of.

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