Open AccessОсобенности фокусировки спиновых волн в кристаллах EuO и EuS
Author(s) -
С.М. Бахарев,
С.П. Савченко,
А.П. Танкеев
Publication year - 2019
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2019.02.47123.205
Subject(s) - brillouin zone , spin wave , condensed matter physics , wave vector , physics , magnon , lattice (music) , lattice constant , magnetic moment , moment (physics) , optics , quantum mechanics , ferromagnetism , diffraction , acoustics
pecificities of spin wave focusing in EuO and EuS crystals are studied. It is shown that spin wave focusing is absent in the long-wave approximation: it is observed only for wave vectors in the second half of the Brillouin zone ( aq $$ \gtrsim $$ π, where a is the lattice constant and q is the magnitude of the wave vector). It was found that, for EuO and EuS crystals, the directions of spin wave focusing differ due to the different signs of the exchange integrals responsible for the exchange interaction of the magnetic moment with the second neighbors. The directions along which a magnon caustic is formed are determined.