Ab initio study of the theoretical strength and magnetism of the Fe−Pd, Fe−Pt and Fe−Cu nanocomposites

0492417 - ÚFM 2019 RIV NL eng J - Článek v odborném periodiku
Káňa, Tomáš - Zouhar, Martin - Černý, Miroslav - Šob, Mojmír
Ab initio study of the theoretical strength and magnetism of the Fe−Pd, Fe−Pt and Fe−Cu nanocomposites.
Journal of Magnetism and Magnetic Materials. Roč. 469, č. 1 (2019), s. 100-107. ISSN 0304-8853. E-ISSN 1873-4766
Grant CEP: GA ČR(CZ) GA16-24711S; GA MŠMT(CZ) LQ1601
Grant ostatní: GA MŠk(CZ) LM2015085
Institucionální podpora: RVO:68081723 ; RVO:68081731
Klíčová slova: Nanocomposites * Ab initio calculations * Theoretical strength * Magnetism
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.); Condensed matter physics (including formerly solid state physics, supercond.) (UPT-D)
Impakt faktor: 2.717, rok: 2019

We studied the Fe−Pd, Fe−Pt and Fe−Cu nanocomposites formed by Fe nanowires embedded in the fcc Pd, Pt
or Cu matrix. The Fe atoms form nanowires oriented along the [0 0 1] crystallographic direction. They replace
second nearest neighbor atoms in the matrix. By means of varying the distance between the nanowires we
arrived to the chemical compositions X15Fe, X8Fe and X7Fe where X stands for Pd, Pt and Cu. The mechanical
and magnetic properties of the nanocomposites were obtained by ab initio simulations. We performed tensile
and compressive tests along the [0 0 1] direction and compared the results with the deformation behavior of the
fcc matrix and the known intermetallic compounds FePd3 and FePt3. It turned out that the maximum attainable
stress for the Fe−Pd and Fe−Pt nanocomposites is higher than the stress attainable for the Pd and Pt matrices.
The maximum stress increased with the increasing Fe content. The increase was due to the enhanced stability in
the nanocomposites described by the C11−C12 > 0 condition. This effect was particularly pronounced in the
Fe−Pt nanocomposites. On the contrary, the Fe nanowires in the Fe−Cu nanocomposites do not enhance the
stability and strength of the Cu matrix. They even make the Cu matrix more compliant to compression.
Regarding the magnetic ground states, the Fe−Pd and Fe−Pt nanocomposites prefer a ferromagnetic configuration
where the spins of all Fe atoms are oriented in parallel manner. On the other hand, the Fe−Cu nanocomposites
exhibit an antiferromagnetic configuration where the spins of all Fe atoms assigned to a particular
nanowire are oriented parallel, but antiparallel to the spins of a neighboring Fe nanowire. The Young modulus
E001 along the [0 0 1] crystallographic direction increases linearly with the Fe content in both the Fe−Pd and
Fe−Pt nanocomposites.
Trvalý link: http://hdl.handle.net/11104/0288941