MnFeP_(0.56)Si_(0.44)B_x合金的磁热效应

Magnetocaloric Effect in MnFeP_(0.56)Si_(0.44)B_x Alloys

研究了MnFeP0.56Si0.44Bx(x=0,0.01,0.02,0.03,0.04)系列合金的物相与磁热效应.室温XRD表明,该系列合金主相均为Fe2P型六角结构,空间群为P62m;B含量为x=0～0.02时,合金存在Fe3Si型第二相,空间群为Fm3m.随着B含量的增加,晶格常数有a增大、c减小的趋势.由M-T曲线可知,随着B含量的增加,合金的居里温度TC线性增加,热滞ΔThys逐渐减小.x=0,0.01,0.02,0.03,0.04时,在外磁场变化为0～1.5T下,由等温M-B曲线得到合金的最大等温磁熵变ΔSM max分别为3.0,4.8,4.3,8.1,10.0J/kg·K.

Phase and magnetocaloric effect in MnFeP0 56 Si0.44 Bx （a： = 0,0.01,0.02,0.03,0.04） alloys have been investigated. X-ray diffraction shows that the alloys mainly crystallize in the Fe2 P-type hexagon- al structure （space group P62m ） with second phase of Fe3Si （space group Fm3m ）,when the B content x=0-0.02. It is found that the lattice parameter a increases and the lattice parameter c slightly decreases with increasing x,and the unit cell volume does not obviously change. From the M--T curves of alloys, it can be found that Curie temperature increases linearly and the thermal hysteresis decreases gradually of the alloys. When x=0,0. 01,0. 02,0. 03,0. 04, the maximal MEC is obtained from the curves of isothermal magnetization for magnetic field change from 0 to 1.5 T is 3.0,4.8,4.3,8.1,10.0 J/kg K,respectively.