Films Grown using Hybrid Molecular Beam Epitaxy*

We present experimental results showing superconductivity in Nd_xSr_1-xTiO₃ thin films (50-250 nm) grown using hybrid MBE approach, where Nd³⁺ is expected to carry net magnetic moment. We measure anisotropic resistance along the two orthogonal in-plane channels. In the high resistance direction we observe a smooth transition from metallic to superconducting state at a critical temperature (T_c ~ 0.2K). However, along the low resistance channel the resistance rises by up to an order of magnitude near T_c before turning superconducting. We discuss these results in the context of anisotropic in-plane Josephson coupling. Furthermore, the out of plane upper critical field (H_c2) as a function of temperature shows opposite curvature from what is expected based on Wethamer-Helfand-Hohenberg theory, and does not saturate down to ~0.12K. We discuss possible explanations, including effects related to magnetic impurities (Nd³⁺) and two-band superconductivity.