Effect of Ag doping on crystallinity and microstrain of LaMnO3 nanoparticles: Confirmations of defect levels with positron lifetime and Doppler-broadening calculations

LaMnO₃ nanoparticles with different levels of Ag doping are prepared and their impact on defect concentration and crystallite sizes are investigated. The crystallinity studies and phase identifications are done with XRD analysis. Williamson-Hall plots and size-strain plots are used to analyse the effect of doping on crystallinity and defect induced microstrain. With the help of Positron Annihilation spectroscopy, the identification of defects and mapping of the defect densities are carried out. Positron lifetime calculations and analysis on Doppler-broadened profile of the positron-electron annihilation radiation in undoped and various doped LaMnO₃ are carried out and compared with W-H plots and size-strain plots.