Superconductivity in Cd₃As₂ thin films

For the first time we observed superconductivity in Cd₃As₂ thin films without applying external pressure. We studied thin (40 nm -100 nm) films of Cd₃As₂ grown on various substrates by two various methods: thermal evaporation and magnetron sputtering from Cd₃As₂ single crystals. Both Raman spectroscopy and X-ray diffraction on the films show results typical for Cd₃As₂ with tetragonal lattice. A zero-resistance state was registered by the four-probe method on Hall bar shaped samples. Also a zero-resistance plateau was observed in dV/dI characteristics at low currents. The superconducting state was suppressed by applying a magnetic field or increasing the current above critical values H_c and I_c, respectively. H_c perpendicular to the film plane was smaller than the in-plane critical field at the same temperature. Analysis of dependences of critical magnetic field H_c on critical temperature T_c reveals a clearly pronounced linear behavior within the intermediate temperature range, similar to that observed for superconducting bulk Cd₃As₂ and Bi₂Se₃ under pressure.