Preparation, structure and superconductivity of Mg 1− xAg xB 2

Abstract

Mg 1− x Ag x B 2 with 0⩽ x⩽10% has been synthesized by the solid-state reaction. The solid solubility limit of Ag at Mg site is around x=0.5%, and the dissolving process of Ag in MgB 2 depends on the starting material. The unit cell and T c of the Mg 1− x Ag x B 2 steadily decrease with doping level. The underlying mechanism of superconductivity suppression by silver doping can be attributed to the chemical pressure effect.