Magneticcorrelations in (FexCo1-x)NGeTe2 vander Waals Crystals
In recent years, two-dimensional (2D) materials have been at the forefront of condensed matter research. The discovery of long-range magnetic order in 2D materials* has catapulted the search for new van der Waals (vdWs) materials with stable magnetic ordering above room temperature. An emergent class of such magnets is the compounds (Fe1-xDx)NGeTe2(N = 3, 4, and 5 and D = Ni or Co). In this talk, I will discuss the state of magnetic ordering over a wide field–temperature phase space in single crystals of the high-Tc ferromagnet (Fe1-xDx)NGeTe2 studied using magnetization, ferromagnetic resonance (FMR), and electrical transport measurements. For the x = 0 compounds, our findings demonstrate an amagnetic phase transition from a collinear to a complex non-collinear magnetic order near the temperature T* ≈ 160 K, below which the magnetic susceptibility is reduced, the FMR linewidth broadened, and the anomalous Hall resistivity suppressed. I will also discuss how the insertion of Co and Ni at the Fe sites affects these results and leads to new magnetic phases.
* 1)Jae – Ung Lee et al (Nano Lett. 16, 7433 (2016))
2) C. Gong et al (Nature 546, 265 (1017)
3) Bevin Huang et al (Nature 546, 270 (2017)
This research has been conducted jointly with postdoctoral associate Rabindra Basnet and funded by the DOD Center of Excellence on 2D materials research under grant No. W911NF2120213.