Anisotropic Resistivity of In-Plane-Aligned La 2-x Sr x CuO 4 (100) Films on LaSrGaO 4 (100) Substrates

We prepared in-plane-aligned La 2- x Sr x CuO 4 (100) films using LaSrGaO 4 (100) substrates by KrF laser ablation. The φ scan of X-ray diffraction and the large anisotropy of resistivity indicate a high degree of in-plane epitaxy. The T c of the in-plane-aligned La 2- x Sr x CuO 4 ( x =0.15) was 21.6 K. The critical temperatures measured along the c -axis were usually higher than those measured along the a -axis. We also observed voltage peaks at just above T c , corresponding to the abrupt decrease of the anisotropy of resistivity at T c .