High-pressure and -temperature synthesis is a powerful tool for synthesizing new intermetallic compounds that cannot be formed using traditional solid-state syntheses. Such metastable compounds can exhibit unrivaled structural complexity, unique bonding, and unusual properties. In the simplest case, there are many binary systems in which no intermetallic compounds are known. These binary phase diagrams feature no thermodynamic intermetallic compounds due to wide miscibility gaps between the constituent elements that persist even at elevated temperatures. Consequently, there exists a dearth in knowledge on the chemical and physical properties of several exciting binary systems. In this dissertation, I report efforts to use high-pressure and high-temperature synthesis to access new metastable binary intermetallic compounds. I have focused on isolating new binary compounds composed of bismuth and a first-row transition metal due to the lack intermetallic compounds in many of these systems. Chapter 1 describes the importance of investigating specifically bismuth binary systems and outlines our synthetic results. Chapter 2 describes the traditional solid-state synthesis and magnetic characterization of two novel misfit layer compounds (BiSe)1.23CrSe2 and (BiSe)1.22(Cr1.2Se2)2. Chapters 3 and 4 are complementary in describing our thorough investigation of the high-pressure phase space of the Cu–Bi binary system. These chapters detail our discovery and physical properties characterization of the first intermetallic compounds in this system, superconducting Cu11Bi7 and CuBi. Chapter 5 describes the in situ discovery of a new high-pressure phase in the Ni–Bi system, -NiBi, and its reversible reconversion to the ambient pressure phase, -NiBi. Chapter 6 complements chapter 5 by establishing the importance of stoichiometry in determining the product of high-pressure synthesis and demonstrating how dimensionality in the Ni–Bi intermetallic system can be controlled by pressure. These results highlight the ability of high-pressure syntheses to allow for inroads into heretofore-undiscovered intermetallic systems for which no thermodynamically stable binaries are known.

Last modified

• 04/03/2019

Creator

• Samantha Marie Clark

DOI

• https://doi.org/10.21985/N23B65

Subject

• Chemistry

Keyword

• intermetallic
• properties
• structure
• synthesis
• high pressure

Date created

• 2018-01-01

Resource type

• Dissertation

Rights statement

• In Copyright