Probing magnetism in exfoliated VI$_3$ layers with magnetotransport

TL;DR

This study investigates the magnetic properties of exfoliated VI3 layers using magnetotransport, revealing a higher Curie temperature than bulk and complex magnetic behavior similar to bulk, demonstrating the effectiveness of transport measurements for 2D magnetism.

Contribution

It provides new insights into the magnetic behavior of exfoliated VI3 layers and demonstrates the use of magnetotransport experiments to probe 2D magnetism.

Findings

Curie temperature of multilayers is 57 K, higher than bulk.

Unusual tunneling magnetoconductance evolution below 40 K.

Easy-axis orientation similar to bulk, with in-plane magnetization components varying across layers.

Abstract

We perform magnetotransport experiments on VI$_3$ multilayers, to investigate the relation between ferromagnetism in bulk and in exfoliated layers. The magnetoconductance measured on field-effect transistors and tunnel barriers shows that the Curie temperature of exfoliated multilayers is $T_C$ = 57 K, larger than in bulk ($T_{\rm C,bulk}$ = 50 K). Below $T \approx$ 40 K, we observe an unusual evolution of the tunneling magnetoconductance, analogous to the phenomenology observed in bulk. Comparing the magnetoconductance measured for fields applied in- or out-of-plane corroborates the analogy, allows us to determine that the orientation of the easy-axis in multilayers is similar to that in bulk, and suggests that the in-plane component of the magnetization points in different directions in different layers. Besides establishing that the magnetic state of bulk and multilayers are similar, our experiments illustrate the complementarity of magnetotransport and magneto-optical measurements to probe magnetism in 2D materials.