Magnetoimpedance Effect in Nanocrystalline Fe86Zr7B6Cu1 Melt-Spun Ribbons

Abstract

The giant magnetoimpedance effect (GMI) in amorphous and nanocrystalline Fe 86 Zr 7 B 6 Cu 1 ribbons has been studied in a wide frequency interval (500 kHz -6 GHz) as a function of microstructure. Selected ribbons have been submitted to conventional and current annealing to induce the amorphous-to-nanocrystalline transformation. A novel technique exploiting a network analyser has been used to evaluate GMI in the high-frequency range (30 MHz-6 GHz). GMI ratios as high as 83% have been found in nanocrystalline samples. A different behavior in the GMI effect has been observed for frequency higher than 100 MHz.

Temperature dependence of magnetoimpedance in annealed Co-based ribbons

“…It relaxes internal stresses and induces a light transverse magnetic anisotropy if the annealing is performed at the presence of magnetic field. It is known that, DC and AC current and furnace annealings produce both stress relaxation and induction of transverse magnetic anisotropy effects, improving the MI response [8][9][10][11][12]. Annealing at open air, below the temperature of crystallization, causes surface oxidation of ribbon and enhances hard magnetic properties of outer layers [13].…”

Modelo Inteligente Para Otimização Da Sensibilidade De Amostras Gmi

“…A magnetização é uma propriedade do material que pode surgir de fontes magnéticas internas ou ser induzida por um campo magnético externo. Assim como o campo magnético externo, a magnetização é uma grandeza vetorial (Crasto, 2003 As ligas metálicas amorfas são fabricadas por meio de várias técnicas, tais como sputtering (Xiao et al, 1999;Panina & Mohri, 2000), eletrodeposição (Sinnecker et al, 2000a, b;Garcia et al, 2001;Atalay et al, 2006), melt spinning (Mehrabian et al, 1978;Coisson et al, 2002), entre outras. Destas, a mais comum é a de melt spinning.…”