Radiation damage effects in CMR manganite materials

Polycrystalline La0.5Pb0.5Mn1−xCrxO3 (x = 0.075 and 0.15) samples have been irradiated with 50 MeV Li3+ ions with different fluences and the effects on the transport properties have been studied by means of the temperature and magnetic field dependent resistivity measurements. Due to Li3+ ion irradiation, the resistivity increases and the metal-insulator transition temperature (Tmi) decreases. At low temperatures (below Tmi), a dominant contribution of the electron-magnon scattering process is observed for all the irradiated and unirradiated samples. The low temperature resistivity behavior as well as the magnetoresistance is modified due to irradiation. The changes in the magnetotransport properties due to irradiation have been compared with the changes caused due to Mn site substitution.