形状记忆效应和电子化合物的电子态

Shape Memory Effect and the Electronic State in the Electronic Chemical Compounds

为进一步发展形状记忆效应的理论,必须把研究基础于电子化合物的电子态和电-声相互作用的量子理论。在这些合金中,电子和离子之间的非球对称相互作用势产生s-d杂化。它对Fermi球的s电子是吸引性的,使它们“虚束缚”于势阱V_k~→,这就对h·c·p·相的形成作出关键贡献。加热到高温,“热声子辐射”和电子的相互作用引起的扰动趋向恢复高对称,它实际起破坏杂化的作用,并释放S电子。恢复了的Fermi球就在(变形的)马氏体内产生大的应力,驱动材料恢复原形。

In proceeding to develope the theory of shape memory effect, we have to place our approach on the quantum theory of the electronic state and electron-phonon interaction in the electronic chemical compounds. In these alloys, the nonspherical symmetric interaction potential between electrons and ions will give rise to the S-d hybridization which is attractive for s electrons in Fermi sphere, makes them becone“virtual bound”in a potentlal well V_k, and thus gives the critical contribution to the formation of h.C.P.. Upon heating to higher temperatures, the perturbation caused by the interaction of “thermal phonon radiation”with electrons tends to recover the higher symmetry. It actually plays the role of destroying the hybridization and seting the s electrons free. The restored Fermi sphere thus produces large strain force in the(deformed)martensite which drives the material back to its original shape.