# Spin Seebeck effect in the layered ferromagnetic insulators CrSiTe$_3$ and CrGeTe$_3$

## TL;DR

This study investigates the longitudinal spin Seebeck effect in layered ferromagnetic insulators CrSiTe3 and CrGeTe3 with Pt films, revealing persistent signals above critical temperatures due to exchange interactions and ferromagnetic correlations.

## Contribution

It demonstrates the LSSE in layered ferromagnetic insulators persists above critical temperatures, supported by numerical analysis of exchange interactions and ferromagnetic correlations.

## Key findings

- LSSE observed in CrSiTe3 and CrGeTe3 layers with Pt.
- LSSE signals persist above critical temperatures.
- Numerical calculations attribute signals to exchange-dominated transport.

## Abstract

We have studied the longitudinal spin Seebeck effect (LSSE) in the layered ferromagnetic insulators CrSiTe$_3$ and CrGeTe$_3$ 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 Y$_3$Fe$_5$O$_{12}$, persists above the critical temperatures in both CrSiTe$_3$/Pt and CrGeTe$_3$/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.