Synthesis and transport properties of La2-xSrxCuO4 thin films deposited by laser ablation

La2-xSrxCuO4 high-Tc thin films are fabricated in situ using second harmonics of a pulsed Nd:YAG laser. Effects of the growth parameters, such as substrate temperature and oxygen pressure, on the physical properties of the films are investigated with resistance and X-ray diffractometry measurements. The films deposited on SrTiO3 (100) and MgO(100) substrates have zero resistance transition temperatures around 22 K. Most grains in these films are aligned with their c-axes perpendicular to the substrates. The current-voltage (I-V) characteristics of a patterned La2-xSrxCuO4 thin film are measured at various temperatures near Tc. From the I-V characteristic curves, it is found that the density (Jc) follows a power law Jc∝(1-T/Tc)n with n∝1.5. Also, the behaviors of the I-V curves are discussed in terms of the scaling theory of the vortex-glass model. (orig.)