Critical behavior and phase diagram of skyrmion-hosting material Co3.6Fe4.4Zn8Mn4 probed by anomalous Hall effect

Abstract

Critical behaviour in magnetism and condensed matter physics is important owing to it’s possibility for understanding the nature of underlying spin-spin interactions, through determination of the critical parameters in the vicinity of a magnetic phase transition. Conventionally, most of the studies on critical behavior were carried out using a magnetic isotherm-based scaling analysis in the vicinity of the transition temperature. However, this conventional magnetometry technique is insufficient for investigation of critical behavior and/or understanding the nature of spin-spin interactions associated with lowering of dimensions (from bulk to thin films) in mesoscopic magnetic devices or in the presence of unconventional magnetic phases. Here, we introduce a magnetotransport approach using anomalous Hall effect (AHE) and evaluate the critical parameters of a structurally disordered skyrmion hosting itinerant ferromagnet Co3.6Fe4.4Zn8Mn4. Comparison of the evaluated critical parameters (β = 0.377, γ = 1.285, δ = 4.408) using AHE shows excellent agreement to the ones obtained from the conventional magnetic isotherm-based scaling analysis. Our results indicate the prevalence of a short-range 3D Heisenberg model in Co3.6Fe4.4Zn8Mn4 with isotropic interaction strength decreasing as r−4.84. The low-field magnetic phase constructed using the AHE-based and magnetic isotherm-based scaling analysis clearly show remarkable agreement, indicating the feasibility of the proposed magnetotransport based technique. The present magnetotransport approach is universal and might be used to understand the modifications of spin-spin interactions or detect the presence of unconventional magnetic phases all the way from “bulk” to mesoscopic magnetic devices.