Unraveling superconductivity in free standing Nb2C MXene studied through magnetic and magneto-transport properties

Abstract

Magnetism in two-dimensional family is hotspot in today’s research due to their promising future technological applications. 2011 redirection the research with the discovery of MXenes with recipe Mn+1Xn at Drexel University, Philadelphia. Chemical scissor mediated nanoscale Nb2CTx is inherited from parent Nb2AlC. Superconductivity aspect in wonder material remained under shadow for little period but theoretical prediction soon diverted attention of the world research community and a lot of efforts are being made to fabricate 2-D superconductors and their possible uses in spintronics. The systematic synthesis process at such 2D MXene is described to produce MXene under optimized condtions using wet chemical etching route. The X-ray diffraction indicates significant increase in c-lattice parameter from 13.92Å to 20.3Å indicating successful etching and intercalation of MXene sheets. Also, c-Lp of Nb2CTx free-standing film is further raised from 20.3 Å to 28.24 Å. A typical 2D layered morphology can be seen through SEM images with well-defined lamellar structure. Magnetic measurements of MXene free-standing film unveil the existence of Type-II superconductivity. Magnetization vs. MT curve under field cooled condition indicates a phase transition from normal to superconducting state at Tc =90K at low temperature with negative magnetization (superconducting diamagnetism) due the formation of vortex state typical of Type-II superconductors. Magneto-transport also reveal the existence of superconductivity by showing a trend toward lower temperature region and large decrease in resistivity. Thus free-standing Nb2C-MXene film is a type-II superconductor with Tc=90K making a significant development towards superconductivity in 2D materials, thus opening a door towards room temperature attainable Spintronics.