ABSTRACT
Multilayer nanogranular films with good soft magnetic properties and high resistivity desired for high frequency applications have been developed in our work. They were prepared by many sequential depositions of thin layers of Co40Fe40B20 and SiO2. After vacuum annealing at 250 degrees C under a uniform in-plane magnetic field of 100 kA/m for 2 hrs, the [Co40Fe40B20 (1.2 nm)/SiO2 (0.8 nm)]30 multilayer nanogranular films have the hard axis coercivity of 210 A/m, saturation magnetization of 1.05 T, resistivity of 2.06 x 10(3) microOmega.cm. Moreover, they show an in-plane uniaxial anisotropy of 2.78 kA/m.
ABSTRACT
By use of the Kubelka-Munk theory, the Mie theory and the independent scattering approximation, we obtain the explicit expression of the emittance of an infrared coating attached to a radar absorber with a high emittance, in the 3~5microm window. Taking aluminum particles with spherical shape as the pigments within the coating, we give the dependence of the coating emittance with respect to the particle radius, the thickness of the coating. At a volume fraction of 0.05, we propose the optimum particle radius range of the pigment particles is around 0.35~0.6microm. When the thickness of the coating exceeds 300microm, the decrease of emittance at 4microm wavelength becomes negligible. Too much thickness of IR layer wouldn't contribute to the decrease of emittance. We study the influence of the infrared coating on the performance of the radar absorber, and believe that not too much thick infrared coating consisting of spherical Al particles wouldn't result in a remarkable deterioration of the absorbing ability of the radar absorber.
