title: Magnetic ordering temperature of nanocrystalline Gd: enhancement of magnetic interactions via hydrogenation-induced "negative" pressure.
abstract: Gadolinium is a nearly ideal soft-magnetic material. However, one cannot take advantage of its properties at temperatures higher than the room temperature where Gd loses the ferromagnetic ordering. By using high-purity bulk samples with grains ~200 nm in size, we present proof-of-concept measurements of an increased Curie point (TC) and spontaneous magnetization in Gd due to hydrogenation. From first-principles we explain increase of TC in pure Gd due to the addition of hydrogen. We show that the interplay of the characteristic features in the electronic structure of the conduction band at the Fermi level in the high-temperature paramagnetic phase of Gd and "negative" pressure exerted by hydrogen are responsible for the observed effect.
authors.affiliation: Institute of Physics CAS, 18221 Prague, Czech Republic.
authors.forename: E A
authors.initials: EA
authors.lastname: Tereshina
authors.affiliation: Center for Computational Materials Science, Vienna University of Technology, A-1060 Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Khmelevskyi
authors.affiliation: Baikov Institute of Metallurgy and Materials Science RAS, 119991 Moscow, Russia.
authors.forename: G
authors.initials: G
authors.lastname: Politova
authors.affiliation: Faculty of Physics, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.
authors.forename: T
authors.initials: T
authors.lastname: Kaminskaya
authors.affiliation: Institute of Low Temperature and Structure Research PAS, 50-950 Wroclaw, Poland.
authors.forename: H
authors.initials: H
authors.lastname: Drulis
authors.affiliation: Baikov Institute of Metallurgy and Materials Science RAS, 119991 Moscow, Russia.|Faculty of Physics, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.|International Laboratory of High Magnetic Fields and Low Temperatures PAS, 53-421 Wroclaw, Poland.
authors.forename: I S
authors.initials: IS
authors.lastname: Tereshina