Phys.org April 23, 2024
An international team of researchers (Japan, Australia) examined magnon spin currents in the ferrimagnetic garnet Tb3Fe5O12 with 4f electrons through the spin-Seebeck effect and neutron scattering measurements. The compound showed a magnetic compensation, where the spin-Seebeck signal reversed above and below K. Unpolarized neutron scattering unveiled two major magnon branches with finite energy gaps which were well explained in the framework of spin-wave theory. Their temperature dependencies and the direction of the precession motion of magnetic moments defined using polarized neutrons explained the reversal at and decay of the spin-Seebeck signals at low temperatures. According to the researchers they illustrated an example that momentum- and energy-resolved microscopic information is a prerequisite to understand the magnon spin current… read more. TECHNICAL ARTICLE
Temperature dependence of the spin current signal and magnon polarization above and below the magnetic compensation temperature. Credit: Yusuke Nambu