Caiyin YOU
材料科学技术（英）
Exchange interaction plays an important role on magnetic properties of nanocomposite magnets consisting of hard- and soft-magnetic phases. Here the exchange interaction in the Sm-Co/Co (and Fe65Co35) magnetic films was characterized by measuring static (mr(H)) and demagnetized (md(H)) remanence curves. According to conventional method: δm(H)=md(H)- [1- 2mr(H)], the exchange interaction was evaluated. The switching fields Hp′ and Hp, at which static (mr(H)) and demagnetized (md(H)) remanence show the fastest change, were identified. The relative ratio of switching fields H0p and Hp has a linear relationship with the maximum value δmmax of δm(H) curves, proposing an alternative way to characterize the exchange interaction.
关键词:
multi-layered films
,
films
,
exchange
,
interaction
Caiyin YOU
金属学报(英文版)
Magnetic properties, phase evolution and microstructures of Pr9.44Fe90.56-xBx (x=7.16 and 4.76) nanocomposite magnets have been investigated. Both as-spun ribbons exhibit two-step demagnetization curves, indicating the feature of partial crystallization. By using differential scanning calorimeter (DSC) measurements, remained amorphous phase of ribbon with x=7.16 shows a higher crystallization temperature. At optimum annealing temperature of 650 ℃ for 10 min, better magnetic properties, Mr=1.01 T, jHc=796 kA/m and (BH)max=136 kJ/m3 were obtained in the sample with x=4.76. Transmission electron microscopy (TEM) observation confirms that the sample with x=4.76 possesses much finer grain size, which causing a better exchange coupling between soft and hard magnetic grains.
关键词:
Nanocomposite magnet
,
melt spinning
,
exchange coupling
,
microstructure
