Nd_4Fe_(77.5)B_(18.5)纳米合金的磁化和反磁行为

Magnetization and Demagnetization Behaviour for Nd_4Fe_(77.5)B_(18.5) Nanocrystalline Alloy

研究了Nd4Fe77.5A18.5纳米合金的高场磁化特性及磁化场高低对其反磁化行为的影响.结果表明，在磁化场μOHmc－7T时，此合金仍没完全饱和．当磁化场Hmc高于某一临界值Hmc时，材料才表现出明显的永磁性．材料的永磁性来源于各相晶粒间的交换耦合作用．

The magnetization feature under high magnetised fields and the effect ofmagnetised field on demagnetization behaviour for Nd4Fe77.5B18.5 nanocrystalline alloy wereinvestigated. The results indicate that the alloy is not saturated magnehsed while magnetiza-tion-field u0,Hm = 7 T. The material shows typical characteristics of permanent magnet asmagnetization-field Hm is larger than a critical magnetization field Hmc. The permanentmagnet features of this alloy origine from exchange-coupling inteaction between crystallinegrains.