Electronic topological transition as an origin of peculiar elastic properties of Ru1-xNixAl superalloys
I. D. Bleskov, E. A. Smirnova, Yu. Kh. Vekilov, P. A. Korzhavyi, B. Johansson, M. Katsnelson, L. Vitos, I. A. Abrikosov, and E. I. Isaev
Fermi surface of a metallic alloy (see enclosed figure) separates occupied and empty electronic states, and therefore it determines many important properties of the material. By changing the alloy composition it is possible to modify the topology of the Fermi surface, giving rise to the so-called electronic topological transition (ETT). W e calculated electronic structure and elastic properties of refractory (Ru,Ni) Al alloys with high melting temperature. The observed peculiarities in elastic constants of the alloys were explained as a result of a ETT occurring upon the increase of Ni content. We showed that there is optimal concentration range up to 40 at. % of Ni for alloying of RuAl by Ni where the elastic constants of Ru1-xNixAl alloys do not change considerably.
High elastic constants in combination with reduced density and high melting temperature allowed us to suggest that (Ru,Ni)Al alloys should be promising refractory materials for gas turbine and jet engine technology.
Calculated Fermi surface cross sections by the (001) and (110) planes for Ru80Ni20Al alloy
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Last updated: 03/08/10