Anomalous Hall effect from inter-superlattice scattering in a noncollinear antiferromagnet

TL;DR

This paper reveals that kinetic control during superlattice growth can create multiple magnetic domains in a single crystal, leading to complex magnetotransport phenomena like the anomalous Hall effect in a noncollinear antiferromagnet.

Contribution

It demonstrates that superlattice domain coexistence can be achieved through kinetic growth control, affecting magnetic and transport properties in a noncollinear antiferromagnet.

Findings

Disparate superlattice domains coexist in a single crystal.

Scattering between domains induces anomalous Hall effect.

Magnetic phases and nanoscale morphology are characterized.

Abstract

Superlattice formation dictates the physical properties of many materials, including the nature of the ground state in magnetic materials. Chemical composition is commonly considered to be the primary determinant of superlattice identity, especially in intercalation compounds. Here, we find that, contrary to this conventional wisdom, kinetic control of superlattice growth leads to the coexistence of disparate domains within a compositionally "perfect" single crystal. We demonstrate that Cr$_{1/4}$TaS$_2$ is a bulk noncollinear antiferromagnet in which scattering between bulk and minority superlattice domains engenders complex magnetotransport below the N\'{e}el temperature, including an anomalous Hall effect. We characterize the magnetic phases in different domains, image their nanoscale morphology, and propose a mechanism for nucleation and growth. These results provide a blueprint for the deliberate engineering of macroscopic transport responses via microscopic patterning of magnetic exchange interactions in superlattice domains.