Ta1−xHfxB: a new FeB-prototype superconductor

Abstract

In this work, we report superconductivity in the new ternary Ta1−xHfxB system. We also show clearly evidence that appropriate amounts of Hf substitution at the Ta site induce the stabilization of the orthorhombic FeB prototype structure in this system. Bulk superconductivity is confirmed by magnetization, electronic transport and specific heat measurements. The Hall signal has temperature dependence and the specific heat data at low temperature deviate from the conventional exponential temperature dependence in Ta0.7Hf0.3B. These results suggest multiband superconductivity in this compound.