Search for New Quantum Materials

Prof. Yew San Hor, Missouri S&T
Guang Bian
Physics Library

Quantum materials such as topological, 2D and nanostructured materials have attracted tremendous attention due to their exotic quantum properties. In this presentation, we will talk about our findings of chemical doping effect in inducing magnetism and superconductivity in chalcogenide compounds. Several interesting physical properties have been observed such as the anomalous Hall effect in Cr-doped Sb2Te3, metamagnetic behavior in Fe-doped Bi2Se3, and the coexistence of ferromagnetism and superconductivity in Nb-doped Bi2Se3 single crystals. We will also present results of the synthesis and characterization of superconducting TaS2 nanowires. Our approach includes the synthesis of 1D charge-density-wave (CDW) TaS3 nanostructure precursors followed by the nondestructive and controlled adjustment of the S composition. TaS3 nanowires show the canonical CDW behavior, but the converted TaS2 nanowires show superconductivity and vortex avalanche behaviors at temperatures below its Tc ~ 3.8 K, which is about three times higher than that of 2D bulk TaS2 crystals. Physical properties of polycrystalline Zn1-xCrxTe samples will also be presented. The samples show metallicity and ferromagnetic behavior for higher Cr doping concentration. Furthermore, optical transparency in the visible light range of these polycrystalline ferromagnetic Zn1-xCrxTe was found to be 40% - 85% for Cr doping concentration up to x = 0.18.