摘要
Chemical doping is a critical factor in the development of new superconductors or optimizing the superconducting transition temperature(T_(c))of the parent superconducting materials.Here,a new simple urea approach is developed to synthesize the N-dopedα-Mo_(2)C.Benefiting from the simple urea method,a broad superconducting dome is found in the Mo_(2)C_(1−x)N_(x)(0≤x≤0.49)compositions.X-ray diffraction results show that the structure of𝛼α-Mo_(2)C remains unchanged and there is a variation of lattice parameters with nitrogen doping.Resistivity,magnetic susceptibility,and heat capacity measurement results confirm that T_(c)was strongly increased from 2.68K(x=0)to 7.05K(x=0.49).First-principles calculations and our analysis indicate that increasing nitrogen doping leads to a rise in the density of states at the Fermi level and doping-induced phonon softening,which enhances electron–phonon coupling.This results in an increase in𝑇T_(c)and a sharp rise in the upper critical field.Our findings provide a promising strategy for fabricating transition metal carbonitrides and provide a material platform for further study of the superconductivity of transition metal carbides.
作者
Longfu Li
Lei Shi
Lingyong Zeng
Kuan Li
Peifeng Yu
Kangwang Wang
Chao Zhang
Rui Chen
Zaichen Xiang
Yunwei Zhang
Huixia Luo
李龙夫;石磊;曾令勇;李宽;余沛峰;王康旺;张超;陈睿;项载琛;张云蔚;罗惠霞(School of Materials Science and Engineering,State Key Laboratory of Optoelectronic Materials and Technologies,Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices,Key Lab of Polymer Composite&Functional Materials,Sun Yat-Sen University,Guangzhou 510275,China;School of Physics,Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices,Sun Yat-Sen University,Guangzhou 510275,China)
基金
supported by the National Natural Science Foundation of China(Grant Nos.12274471 and 11922415)
Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515011168)
the Key Research&Development Program of Guangdong Province,China(Grant No.2019B110209003)
the Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant Nos.2022B1212010008)
Lingyong Zeng was supported by the Postdoctoral Fellowship Program of CPSF(Grant Nos.GZC20233299)
Fundamental Research Funds for the Central Universities,Sun Yat-Sen University(Grant Nos.29000-31610058)。
