We synthesized polycrystalline La3Ni2O7 samples by using the sol-gel method without post-annealing under high oxygen pressure, and then measured temperature-dependent resistivity under various hydrostatic pressures up to 14.5 GPa in a cubic anvil cell apparatus. We find that the density-wave-like anomaly in resistivity is progressively suppressed with increasing pressure and the resistivity drop corresponding to the onset of superconductivity emerges at pressure as low as 7 GPa. Zero resistivity is achieved at 9 GPa below 6.6 K, which increases quickly with pressure to 35.6 K at 14.5 GPa. The observation of zero-resistance state in the polycrystalline La3Ni2O7 samples under high pressures not only corroborates the recent report of superconductivity in the pressurized La3Ni2O7 crystals but also facilitates further studies on this emerging family of nickelate high-Tc superconductors.
@article{arxiv.2309.17378,
title = {Pressure-induced superconductivity in polycrystalline La3Ni2O7},
author = {Gang Wang and Ningning Wang and Jun Hou and Liang Ma and Lifen Shi and Zhian Ren and Yadong Gu and Xiaoling Shen and Hanming Ma and Pengtao Yang and Ziyi Liu and Haizhong Guo and Jianping Sun and Guangming Zhang and Jiaqiang Yan and Bosen Wang and Yoshiya Uwatoko and Jinguang Cheng},
journal= {arXiv preprint arXiv:2309.17378},
year = {2024}
}