paper

Effect of carbon doping on the structure and superconductivity in AlB $_{2}$ -type (Mo $_{0.96}$ Ti $_{0.04}$ ) $_{0.8}$ B $_{2}$

arXiv:2302.14272

Abstract

We report the effect of carbon doping in Ti-stabilized nonstoichiometric molybdenum diboride (Mo $_{0.96}$ Ti $_{0.04}$ ) $_{0.8}$ B $_{2}$ , which exhibits bulk superconductivity below $T_{c}$ = 7.0 K. It is found that (Mo $_{0.96}$ Ti $_{0.04}$ ) $_{0.8}$ (B $_{1 - x}$ C $_{x}$ ) $_{2}$ maintains the AlB $_{2}$ -type phase with a uniform elemental distribution for $x$ = 0.12 and 0.16. The substitution of carbon for boron leads to a slight increase in $a$ -axis, a remarkable reduction in $c$ -axis, the formation of planar defects along the (100) crystallographic planes, and a shift of the B 1 $s$ peaks towards higher binding energies. Contrary to (Mo $_{0.96}$ Ti $_{0.04}$ ) $_{0.8}$ B $_{2}$ , however, no superconductivity is observed down to 1.8 K for the C-doped samples, which is ascribed to the electron filling of boron $I ¨ $ bands resulting from the carbon doping.

18 pages, 7 figures

Effect of carbon doping on the structure and superconductivity in AlB2​-type (Mo0.96​Ti0.04​)0.8​B2​

Abstract

Effect of carbon doping on the structure and superconductivity in AlB $_{2}$ -type (Mo $_{0.96}$ Ti $_{0.04}$ ) $_{0.8}$ B $_{2}$