Physical Properties Revealed by Transport Measurements for Superconducting Nd_(0.8)Sr_(0.2)NiO_(2) Thin Films  

作　　者：Ying Xiang Qing Li Yueying Li Huan Yang Yuefeng Nie Hai-Hu Wen 相英;李庆;李月莹;杨欢;聂越峰;闻海虎(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;National Laboratory of Solid State Microstructures,Jiangsu Key Laboratory of Artificial Functional Materials,College of Engineering and Applied Sciences,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China)

机构地区：[1]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 [2]National Laboratory of Solid State Microstructures,Jiangsu Key Laboratory of Artificial Functional Materials,College of Engineering and Applied Sciences,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China

出　　处：《Chinese Physics Letters》2021年第4期103-110,共8页中国物理快报（英文版）

基　　金：the National Key R&D Program of China(Grant Nos.2016YFA0300401 and 2018YFA0704202);the National Natural Science Foundation of China(Grant Nos.12061131001,11774153,and 1861161004);the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB25000000);the Fundamental Research Funds for the Central Universities(Grant No.0213-14380167)。

摘　　要：The newly discovered superconductivity in infinite-layer nickelate superconducting films has attracted much attention,largely because their crystalline and electronic structures are similar to those of high-T_(c) cuprate superconductors.The upper critical field can provide a great deal of information on the subject of superconductivity,but detailed experimental data are still lacking for these films.We present the temperature-and angle-dependence of resistivity,measured under different magnetic fields H in Nd_(0.8)Sr_(0.2)NiO_(2) thin films.The onset superconducting transition occurs at about 16.2 K at 0 T.Temperature-dependent upper critical fields,determined using a criterion very close to the onset transition,show a clear negative curvature near the critical transition temperature,which can be explained as a consequence of the paramagnetically limited effect on superconductivity.The temperaturedependent anisotropy of the upper critical field is obtained from resistivity data,which yields a value decreasing from 3 to 1.2 with a reduction in temperature.This can be explained in terms of the variable contribution from the orbital limit effect on the upper critical field.The angle-dependence of resistivity at a fixed temperature,and at different magnetic fields,cannot be scaled to a curve,which deviates from the prediction of the anisotropic Ginzburg-Landau theory.However,at low temperatures,the resistance difference can be scaled via the parameter H^(β)| cos θ|(β=6-1),with θ being the angle enclosed between the c-axis and the applied magnetic field.As the first detailed study of the upper critical field of nickelate thin films,our results clearly indicate a small anisotropy,and a paramagnetically limited effect,in terms of superconductivity,in nickelate superconductors.

关 键 词：temperature. field. theory. 

分 类 号：O484.4[理学—固体物理]