用正电子湮没技术研究形变铁的恢复

本文介绍应用正电子湮没寿命和多普勒加宽方法研究60％形变铁等时退火各阶段中缺陷的恢复行为,实验结果说明正电子湮没平均寿命τ及多普勒加宽的S参数都是退火温度的函数,完整晶体中湮没寿命τ_f=111±lPS,缺陷中湮没寿命τ_d=162±lps,本文还根据捕获模型计算了正电子的捕获速率及τ₁,结果证明与理论预期的完全一致,经计算得出捕获正电于的相对缺陷浓度的范围为10^-7-10^-4数量级。关键词：

INVESTIGATION OF THE RECOVERY OF DEFORMED IRON BY POSITRON ANNIHILATION

The recovery behavior of the 60% deformed iron in various stages of isochronal annealing has been investigated by positron annihilation technique. The experimental results show that both the average life time τ and the lineshape parameter S of the positron annihilation may be expressed as functions of annealing temperatures. Life time τ_f of the positron annihilated in the perfect lattice is found to be 111 ± 1 ps, while τ_d in the defect lattice to be 162 ± 1 ps. Trapping rates and τ₁ are calculated, these values are in good agreement with those predicted by trapping theory. It is obtained from the calculation that the rang of fractional concentration of defect trapping positron is 10^-7-10^-4.