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Electrical resistivity and magnetoresistance measurements on (La0.5Pr0.2)Ba0.3MnO3 thin films of 50 and 200nm thicknesses, irradiated by 200MeV Ag+15 ions, have been carried out. Before irradiation, all the films exhibit insulator-metal transition at a temperature (Tp) of ∼200K. After irradiation, both resistivity and Tp remain mostly unaffected in 50nm thin film but vary largely in 200nm thin films. This disparity in irradiation effect on these films is explained to arise from the interplay of columnar defect induced (i) enhancement in resistivity with increasing thickness of the film and (ii) local release of strain at the interfaces of low thickness films, which decreases resistivity.

Grain-size dependence of electronic transport and magnetoresistance (MR) properties of nanostructured La0.7Sr0.3MnO3 (LSMO) manganite thin films on LaAlO3 (100) single crystal substrates prepared using Chemical Solution Deposition (CSD) technique have been studied. The LSMO thin films were annealed at temperatures in the range of 700-1000 degrees C for different time intervals [6 h and 12 h] and crystallized as singlephase LSMO. Microstructural studies carried out using AFM show a marginal increase in the grain-size from 50 to 90 nm as the temperature was varied from 700 degrees C to 1000 degrees C respectively. It has been observed that the insulator-metal transition (T(p)) and MR depend on the grain size. In zero applied field, resistivity reduction is approximately 10(3) at 5 K for the films annealed at 700 degrees C [T(p) approximately 341 K] and 1000 degrees C [T(p) approximately 373 K]. MR versus H isotherms reveal that MR enhances in the vicinity of T(p) but decreases at low temperatures. The results obtained from the electronic and magnetotransport studies are in good agreement with the change in surface morphology of the films studied, which shows that the randomly distributed domains are composed of faceted grains. Synthesizing conditions, annealing temperature and time control the growth and alignment of grains into the domains, which cause better conduction at grain interface.

We have deposited c-axis oriented thin films of La 1.5 Dy 0.5 CaBa 2 Cu 5 O z (La-2125) tetragonal superconductor on LaAlO