Chemical Control of Spin-Phonon Coupling

Abstract

Single-molecule magnets (SMMs) are molecules which retain their magnetic moment without the need for an applied magnetic field. Their development has reached a rapid pace in the last few years, though their properties are only able to be exploited far below room temperature. Popular models exist, and are routinely employed, to maximise the potential magnetic properties of novel compounds, though these rely on a static viewpoint of an inherently dynamic process. To fully model magnetic relaxation in SMMs one must understand the coupling of a molecule's electronic spin with its spatial degrees of freedom (vibrational/phonon modes) since this dictates the operational temperature of an SMM. In order for this spin-phonon or vibronic coupling to be controlled through molecular design we must have a solid understanding of, and ability to calculate, the underlying physics of SMMs. This thesis describes the development of protocols and computer code for carrying out calculations of spin-phonon coupling in a range of lanthanide SMMs. The resulting coupling values are critically assessed by comparison to data obtained from both magnetometry and spectroscopy experiments. Throughout this process, structure-property relationships are uncovered in wellknown SMM families, and some simple design protocols are formulated, paving the way for a more comprehensive understanding of spin-phonon coupling in SMMs.

Date of Award	1 Aug 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Nicholas Chilton (Supervisor) & David Mills (Supervisor)