Short-range ordering in the Ni-Mn-Si based Laves phase Mn(Ni$_{0.6}$Si$_{0.4})_2$

TL;DR

This study reveals the atomic-scale short-range ordering in a Ni-Mn-Si Laves phase, linking it to unique electrical properties, through advanced microscopy and spectroscopy techniques.

Contribution

It provides the first atomic resolution mapping of Si atoms in this phase and explains the origin of short-range ordering.

Findings

Atomic ordering is due to Ni-Si arrangement.

The compound exhibits semiconducting-like electrical behavior.

First atomic resolution Si mapping in this phase.

Abstract

We present the structural ordering and the associated physical behavior of a Ni-Mn-Si Laves phase, Mn(Ni$_{0.6}$Si$_{0.4})_2$. The high-resolution transmission electron microscopy and electron energy loss spectroscopy analysis were performed to resolve a distinct atomic ordering of the system. The study determined the origin of the short-range ordering to be the unique arrangement between Ni and Si atoms. The study also presents the atomic resolution mapping of the Si atoms which has never been reported by any previous studies. With further electrical conductivity measurement, we find one of the consequences of the unique ordering reflected in a semiconducting like temperature dependence of the compound.