大角度晶界的正电子湮没研究

A positron annihilation study on large angle grain boundaries

从两态捕获模型出发,导出了正电子平均寿命与晶粒大小之间的关系,并且预言了晶界正电子饱和捕获效应的存在。在实验上,通过对Zn-22wt％Al合金大角度晶界正电子捕获效应的观察,验证了上述关系,并对大角度晶界正电子捕获效应的一般情况予以讨论。

The relationship between positron mean lifetime and grain size, based on two state trapping model, has been developed, and the saturation trapping at grain boundaries has been predicated. Experimetally, the relationship is tested and verified through the positron trapping at grain boundaries of Zn-22wt.%Al alloys. A general situation of positron trapping at large angle grain boundaries is discussed.