Nanocomposites and nanomaterials

Interplay between the microscopic and macroscopic properties of FINEMET Fe-based micro-ribbons

Yuri Kobljanskyj1, Andrii Sizhuk1, Mykhailo Semen’ko1, Roman Ostapenko1, Zhao Zhenjie2, Sun Zhuo2, Chen Xiaohong2, Oleg Kolesnyk1, Vladimir Malyshev1, Oleksandr Prokopenko1
1Taras Shevchenko Kyiv National University, Glushkova ave. 4g, Kyiv, Ukraine
E-mail: mga@univ.kiev.ua 
2 Shanghai East China Normal University, Shanghai, China
Certain aspects of the connection between the microscopic and macroscopic properties of FINEMET, such as FeCuNbSiB, are discussed with respect to the observed experimental data and the basic theory. 
For example, the X-ray diffraction patterns showed the appearance of the ordered microscopic phases after annealing. The irreversible formation of an ordered microstructures was observed by measuring the magnetic susceptibility during the heating-up of the initially amorphous sample. The peak of ferromagnetic resonance was observed for both crystalline and amorphous phases within the same magnitude of in-plane external magnetic field. The ferromagnetic resonance of the surface electromagnetic wave was also observed for the micro-ribbons by the method of the reflection in the standard rectangular one-mode waveguide (see Fig. 1). The perturbation of the static magnetic field in the ribbon’s plane caused the change in the character of behavior of the micro-ribbons in the low frequency field of an electromagnet. 

Fig. 1. Frequency response curve with VSWR = 1.20 for the as-cast FINEMET sample of the size 12,10 mm×0,60 mm×0,03 mm with the amplification equal to +5dB at the applied external magnetic field (zero (bold dash), greater (dash), and less (solid thin) than the zero value).