The effect of high pressure on the microstructure of annealed amorphous Nd9Fe85B6 alloy was studied. It was found that applica- tion of high pressure made the microstructure of the crystallized alloy much more homogeneous. The average grain size of the Nd2Fe14B phase decreased with the increase of pressure, whereas, the size of the α-Fe first increased when a pressure of 1 GPa was applied and then decreased with further increase of pressure. Pressure-induced (410) texture of the Nd2Fe14B phase was also observed. The present study sug- gested an effective route for controlling the microstructure in a nanoscale solid.
利用基于密度泛函的第一性原理,计算ⅥA族元素Se和Te在常压下的能带结构、电子态密度、弹性系数和德拜温度.能带结构和电子态密度的计算结果表明:Se为间接带隙半导体,Se费米面附近的导带和价带主要来自外层4p4电子的贡献,4s2电子对费米面附近的导带和价带贡献较少;Te为直接带隙半导体,Te费米面附近的导带和价带主要来自外层5p4电子的贡献,5s2电子对费米面附近的导带和价带贡献较少.弹性系数计算结果表明:常压下具有六角结构的Se和Te的力学性质稳定;其德拜温度分别为263 K和315 K.
