Doctoral Dissertations

Keywords and Phrases

Charaterization; high tc superconductor; magnetic topological insulator; quantum materials; syntheissi; topological superconductor


"In this study, attempts were made to grow quantum materials that have recently undergone a profound change of perspective. These materials are involved in intricate macroscopic properties rooted in the subtle nature of quantum physics. To explore our understanding of quantum materials, this study includes three projects: Magnetic Topological Insulators, Topological Superconductors, and high-temperature superconductors.

A Cr-doped Sb2Te3 is added to the category for the magnetic topological insulators project. Their transport properties are studied, and the origin of ferromagnetism is studied. Anomalous Hall effect is observed in the Hall measurements, and serval factors (cooling rate, dopant deficiency) were added in the study. The materials turned into n-type carriers were reported and explained.

For the Topological Superconductor project, Nb-doped Bi2Se3 is added into the category, with a critical temperature of 3.4K. The combination of Topological Insulators and superconductors provides a platform for Majorana Fermions. The symbiosis of ferromagnetism and superconductivity is observed and leads to an abnormal Hall measurement. A possible qualitative mechanism is proposed for the cause.

For the high-temperature superconductor project, several new growth techniques are examined on the delafossite materials CuAlO2. We provide new design principles on growth techniques that would enable the development of transparent conductors"-- Abstract, p. iii


Hor, Yew San

Committee Member(s)

Waddill, George Daniel
Fischer, Daniel
Chernatynskiy, Aleksandr V.
Choudhury, Amitava



Degree Name

Ph. D. in Physics


Missouri University of Science and Technology

Publication Date

Spring 2024


xii, 108 pages

Note about bibliography

Includes_bibliographical_references_(pages 95-107)


© 2023 Yunsheng Qiu, All rights reserved

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 12360