Chemical Control of Vibronic Coupling for Magnetic Materials

Project Information

ContraVib

Grant agreement ID: 851504

DOI

10.3030/851504

Project closed

EC signature date 6 September 2019

Start date 1 February 2020

End date 31 July 2025

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 945 994,00

EU contribution

€ 1 945 994,00

Coordinated by

THE UNIVERSITY OF MANCHESTER
United Kingdom

Periodic Reporting for period 3 - ContraVib (Chemical Control of Vibronic Coupling for Magnetic Materials)

Reporting period: 2023-02-01 to 2024-07-31

Summary of the context and overall objectives of the project

Vibrations in materials allow the exchange of energy between different parts. This fundamental interaction controls magnetism and electronic properties at the nanoscale, and so has important consequences in areas as diverse as data storage, magnetic resonance imaging, efficient lighting, and quantum computing. In the context of magnetism in molecules, vibrations permit switching the magnetic moment, however this occurs in materials spontaneously. Thus, if we hope to control the magnetism of molecules, for instance to make ultra-high-density data storage devices, we must control the coupling between the magnetic properties of molecules and the vibrations. The core objectives of this research programme are to develop a computational method to probe these interactions and understand how they can be controlled with chemistry.

Specifically:

1) Build a computational framework for calculation of the vibrational coupling.
1a) Establish influence of vibrational anharmonicity.
1b) Integrate delocalised vibrational modes.
1c) Investigate vibrational coupling changes in different environments.
1d) Implement ultra-high-quality calculations into the computational framework.
1e) Determine quantum dynamics of spin systems.

2) Collect experimental data to benchmark the computational framework.
2a) Measure magnetic field- and temperature-dependent magnetisation dynamics of molecules in different environments.
2b) Measure electronic and vibrational energies in different environments.
2c) Measure the quantum memory-loss pathway in molecules in different environments.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

We have built a team to achieve the objectives. Direct progress towards the objectives is as follows:

1)
1a) We have calculated the vibrational anharmonicity and are poised to calculate its effect very shortly. Paper A is in preparation.
1b) We have integrated delocalised vibrational modes. Paper B and C are in preparation.
1c) We have built a tool to allow calculation of vibrational coupling in different environments. Yu et al., Chem, 2020, 6, 1777; Reta et al., J. Am. Chem. Soc., 2021, 143, 5943; Kragskow et al., Nature Commun., 2022, 13, 825; paper C in preparation.
1d) We have a plan for how to implement ultra-high-quality calculations into the computational framework.
1e) We have results showing how vibrations lead to loss of quantum coherence in molecules. Paper D is in preparation.

2)
2a) We have measured magnetic field- and temperature-dependent magnetisation dynamics of molecules in different environments. Yu et al., Chem, 2020, 6, 1777; Lu et al., Inorg. Chem. Front., 2020, 7, 2941; Wang et al., Angew. Chem. Int. Ed., 2021, 60, 5299; Thomas-Hargreaves et al., Chem. Commun., 2021, 57, 733; Thomas-Hargreaves et al., Chem. Sci., 2021, 12, 3911; Ding et al., Inorg. Chem., 2022, 61, 227; Gould et al., Science, 2022, 375, 198; Gould et al., Science, 2022, 375, 198.
2b) We have used neutron scattering to measure vibrational energies, but electronic energy measurement has proven more difficult. Garlatti et al., J. Phys. Chem. Lett., 2021, 2021, 12, 8826.
2c) We have measured the quantum memory-loss pathway in molecules in three different environments. Paper E is in preparation.

Other achievements:
- Measurement of magnetic exchange coupling: Giansiracusa et al., Inorg. Chem. Front., 2020, 7, 3909
- Method to extract "hidden" relaxation data from experiments: Reta and Chilton, Chem. Sq., 2020, 4, 3
- Isolation and study of first ferrocene anion: Goodwin et al., Nature Chem., 2021, 13, 243
- Unraveling unexpected magnetism in uranium molecules: Seed et al., Chem, 2021, 7, 1666.
- Assessed accuracy of minimal computational methods: Walisinghe and Chilton, Dalton Trans., 2021, 50, 14130.
- Developed new tools to characterise best molecular magnet to-date: Gould et al., Science, 2022, 375, 198.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

1) We can accurately predict magnetic dynamics of new molecules.
2) We discovered and explained the magnetic properties of the strongest magnet yet made
3) We have made excellent progress towards all objectives.

Expected results:
a) Effect of anharmonicity expounded
b) Effects of different environmental vibrations clarified
c) Understanding how vibrations effect quantum states of molecules
d) Design strategies for weak vibrational coupling