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We report modification of electrical and magnetoresistive properties for the La2/3Sr1/3MnO3/MgO(100) thin films influenced by high power pulsed (  10 ns) laser radiation ( = 532 nm). SEM surface study revealed cracks extended along [100] directions and partially melted material at film surface with radiation power increasing. Low field magnetoresistance typical for high quality intergrain junctions has been measured at T < 240 K for the films with laser beam-induced cracks while partial melting of the material resulted increased electrical resistance, lowering of the paramagnetic to ferromagnetic transition temperature TC and reduced magnetoresistance values in the vicinity of TC. [ABSTRACT FROM AUTHOR]

Polycrystalline sample of single-phase La0.8Sm0.05K0.15MnO3 perovskite compound have been synthesized by solid-state reaction route. X-ray diffraction patterns accompanied by Rietveld-refined crystal structure parameters reveal the rhombohedral structure with space group R 3C. Electrical resistivity infers transition from metallic to insulator phase at 537 K. The application of magnetic field of 8 T, suppresses the resistivity. The metallic resistivity is retraced by considering electron-phonon, electron-electron and electron-spin-fluctuation interactions while insulating behaviour is analysed with small polaron conduction model. [ABSTRACT FROM AUTHOR]