Abstract

Systematic variation of anisotropic X-ray line broadening in vapour-deposited Pb films of various thicknesses on glass substrates is studied using dislocation model of strain anisotropy incorporated into a modified Williamson-Hall and modified Warren-Averbach procedure. For smaller film thicknesses in the range of about 100-200 nm, the dislocation network is less correlated and contains substantial screw component and twin or growth faults. The films of larger thicknesses , on the other hand, consist mostly of edge dislocations with a more regular and correlated dislocation structure. The present study reveals the inadequacy of applicability of conventional Warren-Averbach analysis in regular and correlated dislocation structures