eCommons

 

Hydrides At High Pressures; An Evaluation Of "Chemical Precompression" On The Way To Metallic Hydrogen

Other Titles

Abstract

In this dissertation, we present a theoretical study of compounds rich in hydrogen, focusing on their crystal structure and potential metallization as pressure is applied. Chapter 1 is an introduction to metallic hydrogen; it reviews previous studies and suggests a new way of analyzing the geometric changes that ensue as pressure is applied. Chapter 2 describes the search for structures for SnH4 , using chemical intuition and random search algorithms. Chapter 3 deals with the general problem of segregation which arises as SnH4 , a thermodynamically metastable (positive heat of formation from Sn and 2H2 ) but kinetically persistent compound, is compressed. Chapter 3 is a complement to Chapter 2, as layered structures arise naturally in the low pressure regime, prompting us to explore the subject. Chapter 4 begins an ambitious project which strives to understand the electronic structure and properties of metallic hydrides of the form MH x , where M= Si, Sn and W, and x = 4, 6, 8, 10, 12. For n > 4, there exist van der Waals complexes at lower pressures, but show great variation in structure as they metallize at higher pressures. Chapter 5 explores the effect of impurities in the DOS, as swapping of atoms in structures of stoichiometry Liy[-]1 Bey H. The parent LiBe phase is stable at high pressures; here we attempt to lower the pressure for its metallization by H substitution

Journal / Series

Volume & Issue

Description

Sponsorship

Date Issued

2011-01-31

Publisher

Keywords

High Pressure; dft; Hydrides

Location

Effective Date

Expiration Date

Sector

Employer

Union

Union Local

NAICS

Number of Workers

Committee Chair

Hoffmann, Roald

Committee Co-Chair

Committee Member

Lee, Stephen
Chan, Garnet

Degree Discipline

Chemistry and Chemical Biology

Degree Name

Ph. D., Chemistry and Chemical Biology

Degree Level

Doctor of Philosophy

Related Version

Related DOI

Related To

Related Part

Based on Related Item

Has Other Format(s)

Part of Related Item

Related To

Related Publication(s)

Link(s) to Related Publication(s)

References

Link(s) to Reference(s)

Previously Published As

Government Document

ISBN

ISMN

ISSN

Other Identifiers

Rights

Rights URI

Types

dissertation or thesis

Accessibility Feature

Accessibility Hazard

Accessibility Summary

Link(s) to Catalog Record