Molecular beam epitaxy of superconducting Pr2CuO4 films

Recent reports on superconductivity in parent compounds T′-RE2CuO4 [RE = Pr, Nd, Sm, Eu, Gd] prepared by metal-organic decomposition (MOD) shed new light on the electronic and magnetic phase diagram of electron-doped cuprates. A thorough reduction process is the key to inducing superconductivity in square-planar coordinated cuprates. In this work, Pr2CuO4 films were grown epitaxially by molecular beam epitaxy (MBE) on (001)SrTiO3, (110)GdScO3 and (110)DyScO3 substrates. A modified two-step reduction process is required in order to obtain single-phase superconducting samples. The optimized superconducting properties are Tczero=26K, while the room-temperature resistivity is about 400μΩcm. Hence, we show that even amorphous Pr2CuOy films deposited on (110)DyScO3 become superconducting after the application of the two-step annealing process. These results indicate that superconductivity is induced to Pr2CuO4 by systematic optimization of the reduction conditions, irrespective of the synthesis route.

► MBE preparation of superconducting parent compound Pr2CuO4 with Tc=26K.
► Improved reduction procedures induce superconductivity into Pr2CuO4.
► The way for synthesizing superconducting Pr2CuO4 by other methods is opened.