# 2017 Nevill Mott Medal and Prize

Professor Michael Finnis of Imperial College London, for his original, insightful and courageous work in materials physics, which is recognised worldwide as having consistently opened up large areas of materials physics to rigorous theory and computation.

Professor Michael Finnis is one of the most original and versatile materials physicists in the world.

In 1984 Finnis-Sinclair potentials revolutionised the description of atomic interactions in transition metals by introducing the crucial dependence of metallic bonding on the local atomic environment. These potentials remain the state of the art for multimillion-atom simulations of complex processes in metals.

In his PhD, he explained why the surface layer of most metals is contracted inwards, and why their surface stress is tensile. This was probably the first application of the Hellmann-Feynman theorem in materials physics.

He devised a self-consistent tight-binding model, including dipole and quadrupole polarisabilities, which reconciled the conceptually disparate shell model of ionic materials and the earlier tight-binding formalisms.

He showed how models of cohesion in metallic, covalent and ionic materials may be derived from a single unified and systematic framework in density functional theory (DFT). While full-blown DFT computations may sometimes provide greater numerical accuracy, the insight provided by his analyses is often more useful.

In an invited review of the theory of metalâ€“ceramic adhesion, Finnis analysed the image interaction at such interfaces both classically and quantum mechanically. He led the first DFT calculation of the relaxed atomic and electronic structures of a metalâ€“ceramic interface, which defined the protocols for many subsequent investigations.

Finnis has combined penetrating insight with DFT calculations to prove that embrittlement of copper by bismuth is a size effect. His analysis rigorously distinguished and quantified the contributions of the size of the impurity and changes in chemical bonding induced by segregation. Such a scheme had been sought by physicists for more than half a century.

Finnis pioneered atomistic models for open systems in which chemical potentials are the controlling parameters, and this work spawned the now very active field of ab initio thermodynamics. He has also developed new methods of computational statistical thermodynamics to predict properties difficult or impossible to obtain experimentally, such as solid-liquid interfacial energies and free energies of ultra-high temperature ceramics.

In 2005 he was awarded the Max Born Medal and Prize, awarded jointly by the IOP and the German Physical Society, and in 2014 he was recipient of an Alexander von Humboldt Research Award.