Neutron Scattering Study on Yttrium Iron Garnet for Spintronics

Abstract

Spin current -- a flow of the spin degree of freedom in matter -- has vital importance in spintronics. Propagation of the spin current ranges over a whole momentum space; however, generated spin currents are mainly detected in the long-wavelength limit. To facilitate practical uses of spintronics and magnonics, microscopic understanding of the spin current is necessary. We here address yttrium iron garnet, which is a well-employed ferrimagnet for spintronics, and review {\it in re} the momentum- and energy-resolved characteristics of its magnetism. Using {\it unpolarized} neutrons, we refined its detailed crystal and magnetic structure, and examined magnetic excitations through four decades (10~$\mu$eV-100~meV) using chopper spectrometers in J-PARC, Japan. We also measured mode-resolved directions of the precessional motion of the magnetic moment, i.e., magnon polarization, which carries the spin current in insulators through {\it polarized} neutron scattering, using a triple-axis spectrometer in ILL, France. The magnon polarization is a hitherto untested fundamental property of magnets, affecting the thermodynamic properties of the spin current. Our momentum- and energy-resolved experimental findings provide an intuitive understanding of the spin current and demonstrate the importance of neutron scattering techniques for spintronics and magnonics.

arXiv comment15 pages, 17 figures

References in corpus (24)

• Enhanced Gilbert Damping in Thin Ferromagnetic Films
• Direct electronic measurement of the spin Hall effect
• Experimental observation of the spin-Hall effect in a two dimensional spin-orbit coupled semiconductor system
• Room Temperature Reversible Spin Hall Effect
• Long distance transport of magnon spin information in a magnetic insulator at room temperature
• Theory of magnon-driven spin Seebeck effect
• Linear spin wave theory for single-Q incommensurate magnetic structures
• Thermally driven spin injection from a ferromagnet into a non-magnetic metal
• HORACE: software for the analysis of data from single crystal spectroscopy experiments at time-of-flight neutron instruments
• Magnon Polarons in the Spin Seebeck Effect
• Critical suppression of spin Seebeck effect by magnetic fields
• Thermal spin dynamics of yttrium iron garnet
• Super-Poissonian shot noise of squeezed-magnon mediated spin transport
• The Final Chapter In The Saga Of YIG
• Observation of the Magnon Polarization
• Direct observation of magnon-phonon coupling in yttrium iron garnet
• First-Principles Study of Exchange Interactions of Yttrium Iron Garnet
• Spin transport in a magnetic insulator with zero effective damping
• Noninteger-spin magnonic excitations in untextured magnets
• Quantum thermodynamics of complex ferrimagnets
• Temperature-Dependent Interplay of Dzyaloshinskii-Moriya Interaction and Single-Ion Anisotropy in Multiferroic BiFeO${}_3$
• Magnon mode selective spin transport in compensated ferrimagnets
• Parity Broken Chiral Spin Dynamics in Ba${}_3$NbFe${}_3$Si${}_2$O${}_{14}$
• Neutron-scattering study of yttrium iron garnet

Cited by in corpus (4)

• Magnonic Casimir Effect in Ferrimagnets
• Understanding spin currents from magnon dispersion and polarization: Spin-Seebeck effect and neutron scattering study on Tb3Fe5O12
• Observing Differential Spin Currents by Resonant Inelastic X-ray Scattering
• Neutron polarisation correction to triple-axis data with analytical derivations