The discovery of the so-called giant magnetoimpedance (GMI) effect in Co-based amorphous and nanocrystalline ferromagnetic materials have enabled the development of high-performance magnetic sensors. However, the maximum value of GMI experimentally observed for existing materials has been much smaller than the theoretically predicted value. In order to obtain the suitable value of GMI for practical applications we have used low temperature (77 K) treatment and laser annealing of Co-based amorphous alloys. These combining treatments significantly improve the GMI effect. Co59Fe5Ni10Si11B15 and Co71Fe4Si10B15 amorphous were prepared by the melt-spinning method. GMI measurements were carried out along the ribbon axis with dc magnetic field up to 100 Oe and in the frequency range of 10-1000 kHz. Magneto-optic Kerr effect was used for characterization of surface magnetism in laser annealed Co-based alloys. The magneto-transport properties of these materials were studied by infrared reflection spectroscopy method. Laser annealing of the Co-based amorphous alloys leads to the formation of nanocrystal grain whose size varies between 20 and 50 nm. The value of GMI grows in amplitude about of 2-3 times after low temperature treatment and laser annealing for the abovementioned samples. The measured hysteresis loops as a function of the external magnetic field show the approximately coherent rotation of magnetization. From measurements of the magnetoreflectance in the mid-IR region the relaxation time of conductive electrons was estimated. It was shown that the magnetoreflectance exists in amorphous and nanocrystaline Co-based ribbons due to a change in their conductivity behavior when a magnetic field is applied.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/8023 must be provided.

1. Magneto-optical and Raman spectroscopes of SnO2 doped by Co