Facet-dependent magnon-polarons in epitaxial ferrimagnetic F e3O4 thin films
Abstract
Magnon-polarons are coherently mixed quasiparticles that originate from the strong magnetoelastic coupling of lattice vibrations and spin waves in magnetic-ordered materials. Recently, magnon-polarons have attracted a lot of attention since they provide a powerful tool to manipulate magnons, which is essential for magnon-based spintronic devices. In this work, we report the experimental observation of facet-dependent magnon-polarons in epitaxial ferrimagnetic F e3O4 thin films via spin Seebeck effect measurement. The critical magnetic fields for the magnon-polarons in the (110)- and (100)-oriented F e3O4 films are 1.5 and 1.8 T, respectively, which arises from the different phonon velocities along the [110] and [100] directions. As the temperature decreases, the magnon-polarons-enhanced spin Seebeck voltage decreases in both (110)- and (100)-oriented F e3O4 films, which could be attributed to the enhanced magnon-polarons scattering at elevated temperatures. This work demonstrates the crystal structure engineering in epitaxial magnetic films as a promising route to manipulate the magnon-polarons for future magnon spintronic applications.
- Publication:
-
Physical Review B
- Pub Date:
- November 2020
- DOI:
- 10.1103/PhysRevB.102.184416
- arXiv:
- arXiv:2011.00195
- Bibcode:
- 2020PhRvB.102r4416X
- Keywords:
-
- Condensed Matter - Materials Science;
- Condensed Matter - Mesoscale and Nanoscale Physics
- E-Print:
- 15 pages, 4 figures