Discovery of a new nontoxic cuprate superconducting system Ga-Ba-Ca-Cu-O

作     者：Yue Zhang Wenhao Liu Jin Si Xiyu Zhu Chengping He Haonan Zhao Hai-Hu Wen 

作者机构：Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced Microstructures Nanjing University 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2018年第61卷第9期

页      面：82-85页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0300401,and 2016YFA0401704) the National Natural Science Foundation of China(Grant Nos.A0402/11534005,and A0402/11674164) 

主　　题：cuprates high pressure and high temperature superconductivity 

摘      要：Superconductivity is observed in a new nontoxic cuprate system Ga-Ba-Ca-Cu-O,with T_c=82 K for Ga Ba_2Ca_5Cu_6O_(14+δ)(Ga-1256)and T_c=116 K probably for Ga Ba_2Ca_3Cu_4O_(10+δ)(Ga-1234)or Ga Ba_2Ca_2Cu_3O_(8+δ)(Ga-1223),*** compounds are fabricated by solid state reaction method under high pressure and high *** are characterized by resistivity,magnetization and X-ray diffraction(XRD)*** temperature dependence of magnetization measured in both zero-field-cooled and field-cooled processes on one sample(S1)shows two superconducting transitions at about 82 K and113 *** estimated shielding fraction for the phase with T_cof 82 K is about 67%,while the fraction for another phase with T_(c )of 113 K is quite *** XRD Rietveld refinement for S1 indicates two main phases existing in the sample,Ga-1256 with fraction of about 58%and non-superconducting Ca_(0.85)Cu O_2with fraction of about 42%***,we can conclude the superconducting phase with transition temperature of 82 K is due to *** resistivity measurement also confirms the superconductivity for S1,and the resistivity reaches zero at about 82 *** temperature dependence of magnetization for another sample(S2)shows much higher superconducting shielding fraction for the phase with T_cof 116 K,which may be a promising prospective for the synthesis of Ga-1234 or Ga-1223 phase.