Giant magnetoimpedance effect in Fe79.5P12C6Mo0.5Cu0.5Si1.5 nanocrystalline ribbons

Nanocrystalline structure was observed in Fe79.5P12C6Mo0.5Cu0.5Si1.5 ribbon s after annealed at temperatures from 350 to 500 degreesC. After annealed a t 350 degreesC, the ribbon Fe79P12C6Mo0.5Cu0.5Si1.5 consists of nanoparticl es bcc alpha -Fe(Si, C) and amorphous matrix, Nanoparticles alpha -Fe(Si, C ) and Fe3P appear in Fe79.5P12C6Mo0.5Cu0.5Si1.5 ribbon after annealed at 50 0 degreesC, The giant magnetoimpedance effect was found in nanocrystalline Fe79.5P12C6Mo0.5Cu0.5Si1.5 ribbons. In the frequency range of 0.1-10 MHz, t here is a maximum of magnetoimpedance ratio at 6.9, 1.9, and 1.5 MHz for sa mples with annealing temperatures of 350, 400, and 450 degreesC, respective ly. The value of (Z(0)-Z(65Oe))/Z(0) for the nanocrystalline ribbon Fe79.5P 12C6Mo0.5Cu0.5Si1.5 with annealing temperature 450 degreesC can reach the v alue of 13% at 1.5 MHz. The GMI effect in Fe79.5P12C6Mo0.5Cu0.5Si1.5 ribbon annealed at 500 degreesC is very small (less than 2%). (C) 2001 Elsevier S cience B.V. All rights reserved.