摘要
Despite the recent discovery of superconductivity in Nd_(1-x)Sr_(x)NiO_(2) thin films,the absence of superconductivity and antiferromagnetism in their bulk materials remains a puzzle.Here we report the 1H NMR measurements on powdered Nd0.85Sr0.15NiO2 samples by taking advantage of the enriched proton concentration after hydrogen annealing.We find a large full width at half maximum of the spectrum,which keeps increasing with decreasing the temperature T and exhibits an upturn behavior at low temperatures.The spin-lattice relaxation rate ^(1)T_(1)^(-1) is strongly enhanced when lowering the temperature,developing a broad peak at about 40 K,then decreases following a spin-wave-like behavior ^(1)T_(1)^(-1)∝T^(2) at lower temperatures.These results evidence a short-range glassy antiferromagnetic ordering of magnetic moments below 40 K and dominant antiferromagnetic fluctuations extending to much higher temperatures.Our findings reveal the strong electron correlations in bulk Nd_(0.85)Sr_(0.15)NiO_(2),and shed light on the mechanism of superconductivity observed in films of nickelates.
作者
Yi Cui
Cong Li
Qing Li
Xiyu Zhu
Ze Hu
Yi-feng Yang
Jinshan Zhang
Rong Yu
Hai-Hu Wen
Weiqiang Yu
崔祎;李聪;李庆;祝熙宇;胡泽;杨义峰;张金珊;俞榕;闻海虎;于伟强(Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices,Renmin University of China,Beijing 100872,China;National Laboratory of Solid State Microstructures and Department of Physics,Center for Superconducting Physics and Materials,Collaborative Innovation Center for Advanced Microstructures,Nanjing University,Nanjing 210093,China;Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Mathematics and Physics Department,North China Electric Power University,Beijing 102206,China)
基金
Supported by the National Natural Science Foundation of China(Grant Nos.51872328,11674392,11774401,and A0402/11927809)
the National Key R&D Program of China(Grant Nos.2016YFA0300504 and 2016YFA0300401)
China Postdoctoral Science Foundation(Grant No.2020M680797)
the Fundamental Research Funds for the Central Universities
the Research Funds of Renmin University of China(Grant Nos.18XNLG24,20XNLG19,and 21XNLG18)。
作者简介
崔祎,contributed equally to this work;李聪,contributed equally to this work;李庆,contributed equally to this work;Corresponding authors:俞榕,Email:rong.yu@ruc.edu.cn;Corresponding authors:闻海虎,Email:hhwen@nju.edu.cn;Corresponding authors:于伟强,Email:wqyu_phy@ruc.edu.cn。
