We have studied the longitudinal spin Seebeck effect (LSSE) in the layered ferromagnetic insulators CrSiTe3 and CrGeTe3 covered by Pt films in the measurement configuration where spin current traverses the ferromagnetic Cr layers. The LSSE response is clearly observed in the ferromagnetic phase and, in contrast to a standard LSSE magnet Y3Fe5O12, persists above the critical temperatures in both CrSiTe3/Pt and CrGeTe3/Pt samples. With the help of a numerical calculation, we attribute the LSSE signals observed in the paramagnetic regime to exchange-dominated interlayer transport of in-plane paramagnetic moments reinforced by short-range ferromagnetic correlations and strong Zeeman effects.
@article{arxiv.1908.05807,
title = {Spin Seebeck effect in the layered ferromagnetic insulators CrSiTe$_3$ and CrGeTe$_3$},
author = {Naohiro Ito and Takashi Kikkawa and Joseph Barker and Daichi Hirobe and Yuki Shiomi and Eiji Saitoh},
journal= {arXiv preprint arXiv:1908.05807},
year = {2019}
}