Microstructure, crystallization, and magnetization behaviors in MnBi-Bi composites aligned by applied magnetic field

作者：Liu YS; Zhang JC^*; Cao SX; Zhang XY; Jia GQ; Ren ZM; Li X; Jing C; Deng K

来源：Physical Review B, 2005, 72(21): 214410.

DOI：10.1103/PhysRevB.72.214410

MnBi-Bi composites are fabricated by a magnetic-field-inducing technique under different fabrication fields (0, 0.3, 0.5, and 1 T) and their microstructure and magnetic properties have been investigated. Microstructure results show MnBi crystals are aligned along the c axis in a Bi matrix under relatively moderate fabrication fields (0.5 and 1 T). Magnetic measurement shows a pronounced anisotropy in magnetization in directions normal and parallel to the fabrication field, resulting from this alignment. Interestingly, the fabrication field not only improves the crystal quality of MnBi-Bi composite, but also increases the spin-reorientation temperature T-s of MnBi compound as well as the change in magnetization. On the other hand, an external field applied to the fabricated composite decreases the spin-reorientation temperature T-s. During the reversible transformation from the paramagnetic state to the ferromagnetic state, the magnetic transition temperature T-C increases with the increase of external magnetic field for MnBi compound. Under a field of 10 T, a typical increase of T-C is 20 K during heating and 22 K during cooling, respectively.

• 出版日期2005-12
• 单位上海大学