Direct evidence for positron annihilation from shallow traps

For deformed Ag the temperature dependence of the positron lifetime parameters is followed between 12 and 300 K. Clear direct evidence for positron trapping and annihilation at shallow traps, with a positron binding energy of 9±2 meV and annihilation characteristics very similar to those in the perfect lattice, are revealed. The shallow traps are annealed out below 600 K.