Programme

O.4 -- Oral, ANSWCCMS-2023

Date: Friday, 10 November 2023

Time: 11:00 - 11:30

Statistical mechanics in spin current generation from ferrimagnetic rare earth iron garnet

Adam B. Cahaya

Universitas Indonesia

In a bilayer of ferromagnetic and non-magnetic metal, spin current can be generated via spin pumping. Spin pumping can occur when the system is excited out of equilibrium, by means of ferromagnetic resonance, spin accumulation or thermal gradient. Spin pumping can also occur when the magnetic layer is antiferromagnet or ferrimagnet such as yttrium iron garnet (YIG). Recently, it has been observed that thermal spin pumping can be enhanced by substituting yttrium in YIG by rare earths. The magnetization of rare earth iron garnet arises from iron (Fe) and rare earth (R) magnetic moments. While Fe3+ only has spin angular momentum, R3+ has both spin and angular mementums. Since the origin of spin pumping is spin dependent scattering, the contribution of orbital angular momentum of R to the spin current generation is less studied. Here we study the magnetic coupling between Fe3+ and R3+ in RY2Fe5O12 to understand the contribution of orbital angular momentum to thermal spin pumping. By considering two magnetic sub-lattice model, we analyze the magnetic coupling of the magnetic moments of the ferrimagnetic garnet and show that orbital angular momentum can increase the thermal spin pumping [1]. The result is consistent with experiment [2]. [1] A.B. Cahaya, J. Magn. Magn. Mater. 553, 169248 (2022). [2] Iwasaki, Y., et al. Machine-learning guided discovery of a new thermoelectric material. Sci Rep 9, 2751 (2019).

Presenter: Adam Badra Cahaya