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arXiv · 2012.09453

Unconventional critical behaviour in weak ferromagnets Fe2-xMnxCrAl (0<x<1)

Kavita Yadav·Dheeraj Ranaut·K. Mukherjee
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Abstract

Recent studies on weak ferromagnets Fe2-xMnxCrAl (0<x<1) reveal the presence of cluster glass (CG) and Griffiths phase (GP) below and above the ferromagnetic transition temperature (TC) [(2019) Sci. Rep. 9 15888]. In this work, the influence of these inhomogeneous phases on the critical behaviour (around TC) of the above-mentioned series of alloys has been investigated in detail. For the parent alloy Fe2CrAl, γ is estimated as ~ 1.34, which lies near to ordered 3D Heisenberg model, whereas obtained value of β ~ 0.273 does not belong to any universality class. With increment in Mn concentration, both exponents γ and \b{eta} increases, where γ and β approaches disordered 3D Heisenberg model and ordered 3D Heisenberg model, respectively. The observed deviation in γ and unconventional value of δ can be ascribed to the increment in GP with Mn-concentration. The trend noted for β can be attributed to the increment in CG regime with an increase in Mn-content. The self-consistency and reliability of the estimated exponents are verified by the Widom scaling relation and scaling equations of state. Our studies indicate that the critical phenomenon of Fe2-xMnxCrAl (0<x<1) alloys possibly belong to a separate class and is not described within the framework of any existing universal model.

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Kavita Yadav, Dheeraj Ranaut, K. Mukherjee. 2020-12-17. Unconventional critical behaviour in weak ferromagnets Fe2-xMnxCrAl (0<x<1). https://doi.org/10.1038/s41598-021-98377-y

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