Effects of pressure and doping on Ruddlesden-Popper phases Lan+1 NinO3n+1

Recently, the discovery of superconductivity with a critical temperature Tc up to 80 K in Ruddlesden- Popper phases Lan + 1 Nin O3 n + 1 ( n = 2) under pressure has garnered considerable attention. Up to now, the superconductivity was only observed in La3 Ni2 O7 single crystal grown with the optical-image floating zone furnace under oxygen pressure. It remains to be understood the effect of chemical doping on superconducting La3 Ni2 O7 as well as other Ruddlesden-Popper phases. Here, we systematically investigate the effect of external pressure and chemical doping on polycrystalline Ruddlesden-Popper phases. Our results demonstrate that the application of pressure and doping effectively tunes the transport properties of Ruddlesden-Popper phases. We find pressure-induced superconductivity up to 86 K in La3 Ni2 O7 polycrystalline sample, while no signatures of superconductivity are observed in La2 NiO4 and La4 Ni3 O10 polycrystalline samples under high pressure up to 50 GPa. Our study sheds light on the exploration of high- Tc superconductivity in nickelates.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.