Doctor of Philosophy (PhD)
Physics and Astronomy
Exploration of transition metal stannides, formed from a combination of transition metals (T) and Sn, has resulted in the discovery a variety of materials with interesting physical properties, which is in part due to the complexity of interactions that can occur between the T-d orbitals and Sn-p orbitals. There have been observations of (extremely) large magnetoresistance [1-4], topological flat and nearly flat bands [5-7], superconducting behavior in 2D and 3D systems [5, 8-11], ultrahigh carrier mobility [12-13], and more attributed to d-p orbital mixing in such systems. This dissertation will address the effects of T-Sn interactions on the physical properties of a material through experimental and theoretical investigation on a family of transition metal stannides: Ir3Sn7-xMnx (x = 0 and 0.56), β-IrSn4, and IrSn2.
Doping with a transition metal (Mn) led to the elimination of its predicted pseudo-gap behavior  in Ir3Sn7 and the emergence of spin glass behavior in Ir3Sn6.44Mn0.56. Characterization of the structural, magnetic, electrical, and thermal properties studied in Ir3Sn7-xMnx will be discussed. Investigation of β-IrSn4 and IrSn2 revealed evidence of large magnetoresistance (MR) and quantum oscillations of MR known as Shubnikov-de Haas (SdH) oscillations. Through fast Fourier transformation (FFT) analysis, several frequencies have been identified. A comparative analysis of the behaviors observed in these IrmSnn single crystals will also be presented.
Speer, Smita, "Experimental Investigation of the Physical Properties of IrmSnn (m = 1, 3 and n = 2, 4, 7)" (2022). LSU Doctoral Dissertations. 5936.
Available for download on Wednesday, July 12, 2023