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Second derivatives of the free energy density ͑ FED Љ ͒ , for the 293
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Rotatable anisotropy in exchange-biased CoO/Co epitaxial films deposited on oriented single crystalline MgO(100) and MgO(110) substrates has been discussed. It has been shown that the rotatable anisotropy, usually observed in ferromagnetic resonance experiments in polycrystalline exchange-biased materials, can also be seen by Brillouin light scatte...
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... the in-plane DE frequency variations, observed in BLS experiments, were described with a high precision by the 2 F eff / 2 term Fig. 1a-1c, then, it can be con- cluded that the cos − H 1 term was angle independent; consequently, the spin-wave direction of propagation, ex- pressed by sin − q 1, was kept at constant orientation with respect to the applied field and/or magnetization. Thus, the following formula can be ...
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... the other hand, in the direction perpendicu- lar to the field-cooling direction, where there is no unidirec- tional anisotropy field, the spin-wave frequencies should be modified by the angle-independent rotatable anisotropy and other magnetocrystalline anisotropies. Figures 1a-1c show the relative distance between the biased and non biased data. In the figures, the shapes of functions were calculated using effective anisotropy con- stants obtained from fitting using Eq. 4 to experimental data for the three types of samples: a MgO110 / Co/ CoO, b MgO100 / CoO / Co, and c MgO110 / CoO / Co. Fig. 1 and at 140 K thick continuous lines in Fig. 1. ...
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... anisotropies. Figures 1a-1c show the relative distance between the biased and non biased data. In the figures, the shapes of functions were calculated using effective anisotropy con- stants obtained from fitting using Eq. 4 to experimental data for the three types of samples: a MgO110 / Co/ CoO, b MgO100 / CoO / Co, and c MgO110 / CoO / Co. Fig. 1 and at 140 K thick continuous lines in Fig. ...
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... distance between the biased and non biased data. In the figures, the shapes of functions were calculated using effective anisotropy con- stants obtained from fitting using Eq. 4 to experimental data for the three types of samples: a MgO110 / Co/ CoO, b MgO100 / CoO / Co, and c MgO110 / CoO / Co. Fig. 1 and at 140 K thick continuous lines in Fig. ...
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... for which the second-derivative change was equal to 120.3%. The changes were correlated with the isotropic up- shifts which were equal to 22 10 4 and 40 10 4 J/m 3 rad 2 . It should also be noted that the obtained rotatable behavior was influenced by the twofold and fourfold anisotropy fields after biasing. The smallest rotatable anisotropy Fig. 1a was induced in the sample where there was no twofold an- isotropy before cooling; it was induced after that process, while the fourfold anisotropy remained unchanged Next, in the second case Fig. 1b, the fourfold anisotropy decreased by 48% and the twofold anisotropy increased by 262%. Fi- nally, the strongest rotatable anisotropy Fig. ...
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... that the obtained rotatable behavior was influenced by the twofold and fourfold anisotropy fields after biasing. The smallest rotatable anisotropy Fig. 1a was induced in the sample where there was no twofold an- isotropy before cooling; it was induced after that process, while the fourfold anisotropy remained unchanged Next, in the second case Fig. 1b, the fourfold anisotropy decreased by 48% and the twofold anisotropy increased by 262%. Fi- nally, the strongest rotatable anisotropy Fig. 1c was ob- tained from the sample with the largest fourfold anisotropy reduction equal to 74%. The reduction of the twofold aniso- tropy was equal to 80%. Relative changes of anisotropy con- stants ...
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... Fig. 1a was induced in the sample where there was no twofold an- isotropy before cooling; it was induced after that process, while the fourfold anisotropy remained unchanged Next, in the second case Fig. 1b, the fourfold anisotropy decreased by 48% and the twofold anisotropy increased by 262%. Fi- nally, the strongest rotatable anisotropy Fig. 1c was ob- tained from the sample with the largest fourfold anisotropy reduction equal to 74%. The reduction of the twofold aniso- tropy was equal to 80%. Relative changes of anisotropy con- stants were calculated with reference to room-temperature values, i. ...
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Citations
... In ferrite-doped CoFe films 17 , the rotatable anisotropy comes from the coupling between the doping-host of amorphous NiZn ferrite matrix with CoFe grains, epitaxial L1 0 CoPt (111) thin films 18 . In exchange-biased antiferromagnetic (AFM)/ferromagnetic (FM) bilayers [19][20][21][22][23][24][25] , the rotatable anisotropy is explained by the exchange coupling at the interface of antiferromagnetic and ferromagnetic layers. ...
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