Publications in Scientific Journals:

C. Gruber, P. Bedolla Velazquez, P. Mohn:
"Electronic structure and the magneto-caloric effect";
Journal of Physics: Condensed Matter, 25 (2013), 4360021 - 4360029.

English abstract:
We present a theoretical investigation of the entropy changes upon the application of an
external field leading to the magneto-caloric effect (MCE). The case of localized magnetic
moments is treated within the Weiss molecular field model, but special emphasis is given to
cases of itinerant electron magnetism. These are described within the Landau theory of phase
transitions and the temperature dependence is included via spin fluctuations. Since the
parameters of the Landau expansion can be calculated from first-principles calculations of the
electronic and magnetic structure, an immediate connection to the electronic band structure
and its properties becomes possible. We study ordinary ferromagnets, including
magneto-volume coupling and itinerant electron metamagnets, where in a small external field
range large changes of the magnetic moments occur. We find that such metamagnetic systems
are the most promising candidates for a large MCE in itinerant electron systems. We apply our
expressions to several transition metals and their alloys, as well as to the metamagnets YCo2
and Fe2P, and find reasonable agreement with available experimental data.

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