Doping in MgB 2 superconductors using a high-pressure furnace

Abstract

Since their discovery, there have been many attempts at modifying MgB 2 superconductors by doping them to improve their pinning properties. Although doping was successful, the superconducting transition temperature decreased. Conversely, Ti doping at Mg sites did not work. Here, we tried to make (Mg,Ti)B 2 using a high-pressure furnace. The transport and low-field magnetization measurements showed that Ti could be doped in a uniform manner using the high-pressure synthesis technique. The superconducting transition temperature of the doped material was lower. Magnetic hysteresis curves showed that vortex pinning decreased markedly, even for Ti doping levels as low as 10%.