Publications in Scientific Journals:

S. Khmelevskyi:
"First-principles modelling of longitudinal spin-fluctuations in itinerant electron antiferromagnets: High-Néel temperature in V3Al alloy";
Physical Review B, 94 (2016), 0244201 - 0244208.

English abstract:
The V3Al alloy with DO3 crystal structure belongs to the family of the very few metallic materials that exhibit a
magnetically ordered state with a high ordering temperature (∼600 K) and consist only of nonmagnetic elements.
We show that, similarly to the ferromagnetism in the fcc Ni (with ordering temperature at about 630 K), the
antiferromagnetism in V3Al has itinerant character, and the high value of the NŽeel temperature is the result of
the strong longitudinal spin fluctuations in the paramagnetic state. In order to develop an ab initio-based theory
of the magnetic ordering at finite temperatures, we employ an effective magnetic Heisenberg-like Hamiltonian
with varying values of the on-site magnetic moments. Using a set of approximations we map this model onto
the results of the first-principle-based disordered local moment formalism and the magnetoforce theorem applied
in the framework of the Korringa-Kohn-Rostoker method. Our high-temperature approach is shown to describe
the experimental NŽeel temperature of V3Al very well and thus underlines the importance of the longitudinal
spin-fluctuation mechanism of formation of the vanadium magnetic moment at high temperatures.

Created from the Publication Database of the Vienna University of Technology.