Influence of valence electron concentration over friction coefficient of B2-based approximants

According to the valence electron concentration e/a criterion for approximants, some B2 superstructures may be regarded as a special group of approximants. The present paper reports on an investigation of the friction behavior of this group of phases. The results are compared with data specific to quasicrystals. We show that samples containing the B2 structure and its superstructures exhibit friction coefficients that decrease with increasing e/a and reach minimum at e/a=1.86, i.e. where the quasicrystal is stable. Therefore, the B2-based approximants and quasicrystals belong to a group of phases whose surface properties are mainly determined by electronic structure rather than crystal structure.