Growth and magneto transport studies of topological insulator single crystals

Abstract

The thesis is aims on the single crystal growth of topological insulators and their magneto-transport characterization studies. newlineChapter 1 briefs introduction to Topological Insulator (TI), crystal growth from melt technique is briefly discussed. Characterization techniques such as Powder X-ray Diffraction analysis, Laue diffraction analysis, X-ray diffraction for crystal plane, Scanning Electron Microscopy combined with Energy dispersive X-ray spectroscopy are discussed. Transport properties such as electrical resistivity, Hall measurements, Magneto-resistance measurements are explained briefly. newlineChapter 2 describes the growth of Sb2Te2Se (STS) topological insulator single crystals using vertical Bridgman technique and its magneto-transport characterization techniques. The structure of the grown crystal is identified from powder X-ray diffraction analysis and the structural parameters are derived from Rietveld refinement analysis. The single crystalline nature of the grown crystal is confirmed from Laue diffraction analysis. The grown single crystals are subjected to electrical resistivity, Hall measurement, and Magneto-Resistance (MR) measurements to study the transport behavior of the material. MR shows the Shubnikov-de Hass oscillations above 9 T arise from the surface states of the topological insulator. newlineChapter 3 deals with the growth of Bi1.5Sb0.5Te1.7Se1.3 (BSTS) topological insulator single crystals using modified Bridgman method and its magneto-transport characterizations. newline