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(BiDy) 3 Fe 5 O 12 films were made in the amorphous state by rf magnetron sputtering from a sintered Bi 2 Dy 1 Fe 5 O 12 ceramic target onto quartz substrates and studied by X-ray diffraction. The films were annealed at temperatures ranging from 500 to 700°C for 1 h in air and also at 650°C for different periods of time from 5 to 60 min. X-ray diffraction was used to determined the phase components of the samples. In the X-ray patterns, the amorphous films had two diffuse broad maxima in X-ray diffraction patterns centred at the double diffraction angles 2 θ =31° and 52°, respectively. The films crystallized at 650°C and all the crystallized samples have a single phase of garnet. The FMR linewidth increased with the decreases in annealing temperature and annealing time. No FMR and EPR of Fe 3+ were observed in the amorphous films even though they contained large amounts of Fe 3+ ions, while the EPR of Fe 3+ was observed in slide glass with the same gain.

The magneto-optical Kerr rotation spectra of Fe/Ag, Fe/Au, and Ni/Cu bilayers are measured and calculated based on Fresnel's equations. The theoretical spectra agree with the measured ones. A magneto-optical Kerr effect enhancement peak is observed near 600 and 500 nm for the bilayers Fe/Ag and Fe/Au, respectively, with the Fe layer thickness less than the light penetration depth. No Kerr effect enhancement occurs for Ni/Cu bilayers for any thickness of the Ni layer. It is concluded that the plasma or the absorption edge of the reflector in bilayers is neither a necessary nor a satisfactory condition but provides an important opportunity for the enhancement. Whether the enhancement occurs depends not only on the optical constants of the reflector but also on the optical and magneto-optical parameters of the top ferromagnetic layer.

The effects of the annealing temperature and time on the structure and magnetic properties of the sputtered BiDy-iron garnet films were investigated. X-ray diffraction analysis shows that the as-sputtered films are amorphous. After annealing at about 550°C, amorphous films crystallize into the garnet phase and an unknown phase. The intensity of the unknown phase decreases with increasing annealing temperature and time and vanishes at 650°C for 30 min. It is found that the unknown phase has a large influence on the half-width of the (420) x-ray diffraction peak. The as-sputtered films have a very small magnetization of about 1 emu/g at room temperature. When films are annealed above 570°C, the magnetization increases rapidly with increasing annealing temperature and time.

The magneto-optical Kerr rotation in various bilayer, trilayer and multilayer films are studied experimentally and theoretically. In bilayers and trilayers the enhancement of Kerr rotation by a factor of two to five based on the reduction of effective optical constants has been achieved with a reasonable reflectivity. The enhancement can be realized in the whole wavelength region, from near IR to near UV. In Fe/Pd and FeSi/Cu multilayer films an additional magneto-optical activity related to the exchange polarization of Pd and Cu layers is observed. Multilayer films with broad opportunities for reducing effective optical constants and creating additional magneto-optical activities are demonstrated to be a promising area for finding new magneto-optical materials.

The experimental magneto-optical Kerr rotation spectra of Fe/Ag compositionally modulated films reported by Katayama et al. are studied theoretically. It is found that the free electrons of Ag are spin polarized. The magnitude of the polarization is about 1% with a direction opposite to that of Fe. The polarized Ag also gives rise to an additional magneto-optical activity as in Pt and Pd.

The magneto‐optical polar Kerr rotation spectra and reflectivity spectra in the wavelength region 400–700 nm are studied for Fe/PbTe and Fe/Pb bilayer films. Large Kerr rotation enhancement with high reflectivity was observed. The experimental data of reflectivity are nearly consistent with theoretical calculation using Fresnel’s equations. However, the observed Kerr rotation spectra behavior is quite different from that expected by macroscopic optical theory.

To analyze fuzzy data in uncertain evidential reasoning, some researchers have recently extended the D-S evidence theory to fuzzy sets. But there are some insufficiencies in the definition of the fuzzy belief function and the combination rule on fuzzy sets of the D-S evidence theory. This paper describes a new definition of the similarity degree between two fuzzy sets and the improved extension combination rule of the evidence theory on fuzzy sets. It also presents the corresponding mathematical proof to validate the improved combination rule. Compared with other generalizing combination rules, the results of the numerical experiments show that the new combination rule in this paper can acquire more changing information to the change of fuzzy focal elements more effectively, and it overcomes the insufficiencies of other existing combination rules and enhances the robustness of fusion decision systems effectively.

This paper introduces improved combination rules for the D-S evidence theory for resolving the problem of evidence conflicts and also provides the mathematical proofs for these rules. The improved rules allocate the conflicts to various focal elements according to the credibility of the coherence evidence. We adopt the AND-algorithm to combine the coherence evidence, which reflects the intersection of focus elements. Our theoretical analysis and numerical examples prove that the given rules are rational and effective for both highly conflicting and coherent evidence.

Crystalline Co spinel ferrite films were prepared by rf sputtering on glass substrates without buffer layer and annealed at temperatures from 400 to 600 °C for 2 h in air. (100) texture was obtained in these films. The anisotropy constant, magnetic hysteresis loops, and magneto‐optical Faraday spectra of the films were measured. The texture became poor when the films were annealed below 500 °C, but the perpendicular anisotropy constant Ku, squareness ratio R=(Mr/Ms)⊥/(Mr/Ms)∥ increased and showed peak values of 2.2×105 ergs/cm3 and 0.94, respectively, at an annealing temperature Ta=500 °C. For the film annealed at 600 °C (higher than the Curie temperature, 520 °C, of Co spinel ferrite), the texture recovered, but Ku and R dropped. The Faraday rotation spectra of Co spinel ferrite films showed a broad peak centered around 720 nm. The peak value increased monotonically with increasing annealing temperature. These results may be related to the Co ion‐induced anisotropy and Co ion distribution in tetrahedral ...

Theoretical and experimental studies of θ K spectra demonstrated that the conduction electrons of Ag in Fe/Ag CMF are spin polarized and give an additional MO activity. In FeCo/Cu/FeCo sandwiches, an oscillation of θ K with changing thickness of Cu was observed, which may indicate an oscillatory spin polarization of Cu layers.

An approach is proposed and shown by numerical calculations to shift the enhancement peak of the magneto-optical Kerr rotation of the metallic bilayers of recent interest to the wavelength of semiconductor laser.

Bilayers Fe/Au‐Cu and Fe/Ag‐Au made by vacuum evaporation were studied. The magneto‐optical polar Kerr rotation and reflectivityspectra were measured in the region from 400 to 700 nm. In the magneto‐optical Kerr rotation spectra of bilayers Fe/Au‐Cu and Fe/Ag‐Au with the thickness of Fe layer less than the light penetration depth, there is a broad enhancement of the magneto‐optical polar Kerr rotation with a Kerr peak near the plasma edge in the reflectivityspectra of Au‐Cu and Ag‐Au alloys. The peak shifts toward the long wavelength side with increasing Cu and Au content in Au‐Cu and Ag‐Au alloys, respectively. Our results show that the composition of the reflector in our bilayer structures can shift the wavelength range of the magneto‐optical Kerr rotation enhancement. Interpretation and discussions are given.

Avec une couche reflechissante de metal noble, la rotation de Kerr des bicouches metalliques peuvent etre augmentees par un facteur de deux, avec une reflectivite superieure a 45%, et un gain dans la figure de merite de 70%, autour de la longueur d'onde de 800 nm

Magneto-optical Kerr rotation (MOKR) spectra of single films Nd-Fe and bilayers NdFe/Cu, NdFe/Al made on glass substrates by vacuum evaporation were measured. It is found that there is a broad enhancement on MOKR spectra for bilayers NdFe/Cu and NdFe/Al and a Kerr peak for NdFe/Cu bilayers.

Magnetic measurements, ferromagnetic resonance, magneto-optical Kerr rotation and nuclear magnetic resonance have been used to study the spin polarization of nonmagnetic layers of Pd, Cu, Ag and Al in multilayers and sandwiches containing Fe, Co, FeCo and CoCr. The existence of the spin polarization of Pd, Cu, Ag and Al was demonstrated directly or indirectly.

It is shown that low optical constants of the reflecting substrate of metallic bilayers for magneto-optical Kerr effect (MOKE) enhancement can be obtained around wavelength 800 nm either in a thin noble metal layer or in a dielectronic/noble metal double layer reflector. Analyses also indicate that low optical constants can be obtained at any visible/near infrared wavelength with a dielectric/metal double layer. A method of designing the magnetic layers for MOKE enhancement is proposed.

In the magneto-optical polar Kerr rotation spectra of Fe/Au-Cu bilayers made by vacuum evaporation with the thickness of Fe layer less than the light penetration depth, a broad enhancement of the Kerr rotation spectra occurs near the absorption edge in the reflectivity spectra of Au-Cu alloys and shifts towards the longer wavelength side when the content of Cu in the Au-Cu reflector increases. For Fe/Al-Cu bilayers made by rf magnetron sputtering with a small content of Al in the Al-Cu reflector a peak occurs in its Kerr rotation spectrum. When the content of Al becomes larger the Kerr rotation increases with the decrease of wavelength monotonically and an enhancement occurs in the short wavelength region.

Bilayers Nd‐Fe/Cu and Nd‐Fe/Al made by vacuum evaporation were studied. The magneto‐optical Kerr effect (MOKE) and reflectivity spectra were measured. For Nd‐Fe/Cu with low Nd content and small thickness of Nd‐Fe layer there is a peak in the MOKE spectrum and a broad MOKE enhancement. The position is located near the plasma edge of Cu. When the content of Nd exceeds 37 at. %, there is no Kerr peak in the MOKE spectrum of Nd‐Fe/Cu. When the thickness of the magnetic layer is larger but still less than the light penetration depth, the position of the peak moves towards the long‐wavelength side. For Nd‐Fe/Al there is a broad enhancement in the short‐wavelength region, but no Kerr peak occurs no matter how the magnetic layer changes. The results presented show that the necessary conditions for MOKE enhancement in bilayers are suitable values of n and k of the reflector, whether the reflector has a plasma edge or not, and the enhancement also depends on the properties of the magnetic layer.

(BiDy)Fe5O12 films in the amorphous state were made by rf magnetron sputtering from a sintered Bi2DyFe5O12 ceramic target onto quartz substrates and confirmed by x‐ray diffraction. The films were annealed at different temperatures ranging from 500 to 800 °C for 1 h in air. The crystallization temperature was about 650 °C, as measured by DTA method. Magnetization M versus temperature relation of well crystallized films showed both a compensation temperature Tcomp (80 K) and Curie temperature TC (563 K). The M‐T curve from 1.5 to 600 K of amorphous film showed no definite TC or Tcomp; M measured in a field of 20 kOe decreased monotonously. The Faraday rotation (500–700 nm) of amorphous films was small. The M and Faraday rotation (633 nm) increased rapidly at the crystallization temperature. The Bi ion induced peak (550 nm) in the Faraday spectra got higher with the increasing annealing temperature and was up to 9.14 degree/μm. The Faraday spectra of films annealed at 650 °C for different times showed that t...

The magneto-optical Kerr rotation of thin ferromagnetic film (Co, Ni, and Fe) is studied experimentally and theoretically. The Kerr rotation of magnetic/air structures is found to be enhanced a lot even when the thickness of magnetic layer is very small. Numerical calculation also indicates that if a thin magnetic layer is sandwiched between two dielectric layers of the same optical constants, the Kerr rotation does not drop as the thickness is decreased.