Electrodeposited rhenium sandwich structures with thermal expansion mismatch and the superconducting transition behaviors

Abstract

The effects of stress and strain on the superconducting transition behavior of electrodeposited Re film are investigated using sandwich structures, where a thin Re layer is deposited in between thicker metal layers with different coefficients of thermal expansion (CTE), such as Cr and Cu. The entire sandwich structures are prepared using electrodeposition at room temperature. Cyclic voltammetry is conducted to characterize the electrochemical behavior of metal deposition. X-ray fluorescence, scanning electron microscope, X-ray diffraction, electrical resistance measurements at cryogenic temperature, and in-situ X-ray diffraction are utilized to characterize the electrodeposited films in the stacks. The Re films sandwiched between metals with different CTEs show different superconducting transition and recrystallization behaviors. This study provides an innovative method to inhibit grain growth and to maintain an enhanced critical temperature of the electrodeposited amorphous superconducting Re.