The loss of anisotropy in MgB2 with Sc substitution and its relationship with the critical temperature

Ruiz-Chavarria, Sabina; Tavizon, Gustavo; de la Mora, Pablo

The loss of anisotropy in MgB2 with Sc substitution and its relationship with the critical temperature

Authors

Ruiz-Chavarria, Sabina

Tavizon, Gustavo

de la Mora, Pablo

Description

The electrical conductivity anisotropy of the sigma-bands is calculated for the (Mg,Sc)B2 system using a virtual crystal model. Our results reveal that anisotropy drops with relatively little scandium content (< 30%); this behaviour coincides with the lowering of Tc and the reduction of the Kohn anomaly. This anisotropy loss is also found in the Al and C doped systems. In this work it is argued that the anisotropy, or 2D character, of the sigma-bands is an important parameter for the understanding of the high Tc found in MgB2.