Observation of enhanced spin-spin correlations at triple point in 2D ferromagnetic Cr2X2Te6 (X=Si, Ge)

TL;DR

This study investigates the spin-spin correlations in 2D ferromagnetic Cr2X2Te6 (X=Si, Ge), revealing a triple point where magnetic phases coexist and correlations are significantly enhanced, using a magnetoelectric measurement approach.

Contribution

It provides the first detailed phase diagram and demonstrates enhanced spin-spin correlations at the triple point in these 2D ferromagnets.

Findings

Triple point identified around TC and 1 kOe where phases coexist.

Maximum spin-spin correlations occur at the triple point.

Cr2Si2Te6 exhibits stronger correlations than Cr2Ge2Te6.

Abstract

The domain dynamics and spin-spin correlation of 2D ferromagnets Cr2X2Te6 (X=Si, Ge) are investigated by a composite magnetoelectric method. The magnetic field-temperature phase diagrams for both in-plane and out-of-plane magnetic fields disclose a triple point around TC and 1 kOe, where ferromagnetic, paramagnetic, and spin-polarized phases coexist. The magnetoelectric signal shows peak features at the phase boundaries and reaches the maximum at the triple point, suggesting significant enhancement of spin-spin correlations at this point. A comparison between two systems reveals that the spin-spin correlations in Cr2Si2Te6 are stronger than that in Cr2Ge2Te6.