Ion implant-induced change in polyimide films monitored by variable energy positron annihilation spectroscopy

Modification of microstructure of the surface and the bulk in ion-irradiated membrane studied using positron annihilation spectroscopy

“…A and n are the material dependent constants (Schultz and Lynn, 1988;Coleman, 2002). For polymers, the values of A and n are generally taken as 40 and 1.6, respectively (Xie et al, 1995;Myler et al, 1998). Doppler broadening spectroscopy (DBS) using a slow positron beam has evolved as a useful technique to characterize the microstructure of a polymer membrane as a function of depth (Kobayashi et al, 1995;Dlubek et al, 2000;Saito et al, 2007).…”

Damage-depth profiling of ion-irradiated polyimide films with a variable-energy positron beam

“…10 The usefulness of this technique for the study of organic polymers was recently examined. [11][12][13][14][15][16][17][18][19][20] However, positron annihilation in polymers is more complex than in metals or semiconductors because a certain fraction of the positrons can combine with an electron to form a hydrogen-like bound state called positronium (Ps). 21 We show that the irradiation of PIs with high energetic ions led to an inhibition of Ps formation.…”