The role of Mn in Bi2-xMnxTe3 topological insulator: Structural, compositional, magnetic, and weak anti-localization property analysis

Bi2Te3 is one of the favorite materials in material-science community due to its well-known topological and thermoelectric properties. In this paper, we have explored the influence of magnetic (Mn) doping on structural, compositional, and magneto-electric transport properties of host Bi2Te3. Bi2-xMnxTe3 (where x = 0, 0.05, and 0.25) has been prepared using the programmable heat treatment of vacuum-sealed precursors. XRD profiles along with Rietveld refinement infer that, most of the doped-Mn atoms substitute Bi-sites and few Mn-atoms take interstitial positions in host Bi2Te3. This phenomenon is also supported by the XPS and HR-TEM study. The magnetic analysis establishes that the nature of magnetism changes from diamagnetic to paramagnetic with the increment of Mn-content. However, there exists Griffith phase at low temperatures in the paramagnetic background. Electrical transport indicates the preservation of hostʼs metallic nature for low Mn-doping; however, an anomaly in ρxx\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\uprho }_{\mathrm{xx}}$$\end{document} –T plot at 100 K is noticed for high Mn-doping, which justifies the influence of magnetic dopants in electron transport. Importantly, this magnetic doping has a strong impact on hostʼs quantum-transport, as there exists a gradual transformation of hostʼs weak anti-localization (WAL) effect into quadratic as well as fluctuating nature in the magneto-conductance (MC) study.