Synthesis of infinite-layer nickelates and influence of the capping-layer on magnetotransport

The recent discovery of a zero-resistance state in nickel-based compounds has generated re-excitement about the long-standing problem condensed matter high-critical-temperature superconductivity, light analogies between infinite-layer nickelates and cuprates. However, despite some formal valence crystal symmetry analogies, electronic properties are remarkably original accounting, among other properties, unique Nd5d-Ni3d hybridization. This designates as new class oxide superconductors which should be considered on their own. Here we report Nd1-xSrxNiO2 (x = 0, 0.05 0.2) thin films synthesized with without SrTiO3 capping-layer, showing very smooth step-terraced surface morphologies. Angle-dependent anisotropic magnetoresistance measurements performed magnetic field rotating in-plane or out-of-plane respect to sample surface, rendered important information undoped SrTiO3-capped uncapped samples. results point at key role capping-layer controlling magnitude anisotropy properties. We discuss this control terms combined effect Nd-Ni hybridization an intra-atomic exchange coupling Nd-4f Nd-5d states, latter essentially contributing (magneto)transport. Further studies foresee influence capping layer no rare-earth.