Direct observation of the temperature variation of the short positron lifetime in metals by using the positron age-momentum correlation technique

The short lifetime component of the positron lifetime spectrum for Zn has been reconstructed from the positron age-momentum correlation data. It is shown that the vacancy formation energy can be determined only from the data measured at temperatures considerably lower than the melting point. This method directly confirms the temperature dependence of the short lifetime component predicted by the two-state trapping model.