Vacancy formation energy for indium determined by a positron annihilation technique

Abstract

A method to determine the vacancy formation energy ${E}_{v}$ from the measurement of the Doppler broadening of annihilation radiation is reported. The S parameter for the trapped positrons ${S}_{v}$ that is necessary for the analysis is determined independently by using the positron annihilation age-momentum correlation technique. The method is applied to indium, whose ${E}_{v}$ is difficult to measure by the usual Doppler broadening measurement, because the ${S}_{v}$ is not determined clearly due to the absence of the saturation trapping of the positrons. The ${E}_{v}$ determined is $0.48\ifmmode\pm\else\textpm\fi{}0.02$ eV.