Plasma-enhanced pulsed-laser deposition of single-crystalline M o2 C ultrathin superconducting films

Transition-metal carbides (TMCs) possess many intriguing properties and inspiring application potentials, and recently the study of a two-dimensional form of TMCs has attracted great attention. Herein, we report successful fabrication of continuous Mo2C ultrathin single-crystalline films at 700°C with an approach of plasma-enhanced pulsed-laser deposition. By sophisticated structural analyses, the Mo2C films are characterized as single crystal with a rarely reported face-centered cubic structure. In further electrical transport measurements, superconductivity observed in the Mo2C films demonstrates a typical two-dimensional feature, which is consistent with Berezinskii-Kosterlitz-Thouless transitions. Besides, large upper critical magnetic fields are discovered in this system. Our work offers an approach to grow large-area and high-quality TMCs at relatively low temperatures. This study may stimulate more related investigations on the synthesis, characterizations, and applications of two-dimensional TMCs.