Fe-Nd-Al系非晶合金条带的磁性机理

Mechanism of the Magnetic Behavior in Fe-Nd-Al Amorphous Alloy Ribbons

对Fe_(53)Nd_(37)Al_(10)合金甩带速度为40和20 m/s条带样品的磁性能、磁粘滞行为和微观结构进行研究,分析了该合金条带的矫顽力机理。结果表明:Fe_(53)Nd_(37)Al_(10)合金甩带速度为40和20 m/s条带样品的剩余磁化强度M_r分别为33.50和36.05(A·m^2)·kg^(-1),矫顽力_iH_c为62.00和121.50 kA/m。40 m/s条带样品的热涨落场H_f,激活体积V_a和激活直径D_a分别为2.47 m T,3.90×10^(-18)cm^3和19.53nm;而20 m/s条带样品为2.73 mT,3.53×10^(-18)cm^3和18.89 nm。40 m/s条带样品里面存在直径小于5 nm的纳米团簇,而20 m/s条带样品的纳米团簇直径为5~10 nm,且纳米团簇数量更多。Fe-NdAl非晶条带里面同时存在交换耦合和钉扎2种作用,纳米团簇的尺寸和数量,以及多个团簇组成的作用单元是影响非晶条带矫顽力的主要原因。

Ribbons of the Fe53Nd37Al10 alloy with different cooling rates, 40 and 20 m/s, were prepared by a melt spinning method. The magnetic behavior, magnetic viscosity behavior and microstructure of the ribbons were investigated. The remanent magnetization Mr of the ribbons with the cooling rate of 40 and 20 m/s is 33.50 and 36.05（A？m2/kg）, and the coercivity iHc is 62.00 and 121.50 kA/m, respectively. The fluctuation field Hf, activation volume Va and activation diameter Da of the ribbons with the cooling rate of 40 m/s are 2.47 m T, 3.90×10-18cm3 and 19.53 nm, respectively. The Hf, V a, and Da of the ribbons with the cooling rate of 20 m/s are 2.73 mT, 3.53×10-18 cm3 and 18.89 nm, respectively. The size of nanoclusters in the ribbons with the cooling rate of 40 m/s is less than 5 nm. However, the size of nanoclusters in the ribbons with the cooling rate of 20 m/s is 510 nm and there are more nanoclusters in the ribbons. The hard magnetic property of the ribbons melt-spun at 40 and 20 m/s would be due to the exchange coupling interactions and pinning effect. The main influencing factors of the coercivity of Fe-Nd-Al amorphous alloy ribbons are the size and amount of nanoclusters and the interactive units composed of many nanoclusters.