Temperature dependence of positron trapping in a quenched Al-1.5×10-2at%Si alloy

Doppler-broadening measurements of positron annihilation in quenched single-crystal Al-1.5*10 -2 at%Si show a reversible temperature dependence of the annihilation characteristics which varies according to the defect state of the crystal. This effect seems to be largely able to account for an apparent discrepancy between data for quenched samples measured at 78K and at higher temperatures.