Laser irradiation of SrTiO3 single crystals

Excimer laser irradiation (248 nm, 34 ns) of SrTiO3(100) single crystals wa s studied in order to resolve the feasibility of obtaining well-defined pat terned structures. Spots irradiated with a single pulse in the 0.4-1 J/cm(2 ) fluence range presented a pattern of cracks along crystallographic direct ions, which do not propagate beyond the borders, and no ejected material wa s observed on the non-irradiated areas. Arrays were patterned by translatin g the single crystal, and different morphologies were found depending on th e width of the tracks. Tracks 10 mu m wide or more developed a pattern of c racks, whereas 3 mu m wide tracks did not. Artificial arrays in magnetoresi stive La2/3Sr1/3MnO3 thin films were prepared by using SrTiO3(100) single-c rystal substrates in which arrays had been previously patterned. The interf aces originated a substantial low-field tunnel magnetoresistance.