On Roger Elliott’s 60th birthday, a conference in his honour displayed beneath his photograph the title: “Disorder in Condensed Matter Physics”. This reference to his speciality in theoretical physics, where he made important contributions to theories of optical, magnetic and semiconductor properties of the solid state, was ironic, for Elliott, who has died aged 89, was a man of the soundest judgment.
His opinion was widely sought and highly regarded, as professor at Oxford University (1974-96), as chief executive of Oxford University Press (1988-93), and in national affairs, as physical secretary and vice-president of the Royal Society (1984-88) and vice-chairman of the Parliamentary Office of Science and Technology (1990-93).
Elliott investigated how the scattering of light and of neutrons can reveal the structure of matter on the molecular and atomic scale. A neutron has no electric charge overall, but contains swirling electric charges within, which give rise to magnetism. The neutron can thus be used as a probe of the magnetic structure of materials. When individual neutrons are scattered by a sample of a material, their statistical accumulation at different positions beyond the sample can be decoded by means of quantum theory to determine the material’s structure. The loss or gain of energy by the neutrons can also reveal information about the substance.
Analysis and interpretation of the results relies heavily on quantum mechanics, and it was Elliott’s theoretical work in this area that inspired many experiments at the Institut Laue-Langevin in Grenoble, which is one of the world’s most intense neutron sources, founded in 1967. He was a member of its scientific council from the earliest days, and his work also underpinned the founding of the ISIS neutron and muon source at the Rutherford Appleton Laboratory in Oxfordshire.
The response of materials to the presence of magnetic fields held a lifelong fascination for him, and helped inspire study of the field of quantum phase transitions. Normal phase transitions, such as from ice to water to steam, are characterised by a sudden change in a property of the material. Quantum phase transitions deal with transitions among different phases of matter at the absolute zero of temperature – minus 273C – when some physical parameter changes.
He made a number of contributions to the theory of the magnetic structures of the rare-earth metals in which the magnetic forces that individual atoms can exert on electric currents are arranged in a spiral. He explained why this unusual type of ordering occurs.
In the theory of semiconductors he was the first person to include the interaction between the electrons’ motion and their intrinsic spins – in effect, their magnetic orientation. This work has leaped to prominence recently because of the desire to increase the functionality of semiconductors by using information stored in the electrons’ spins – so-called “spintronics”.
Born in Chesterfield and raised in Swanwick, Derbyshire, Roger was the son of James Elliott, a policeman, and his wife, Gladys (nee Hill). When he was three, his father died of tuberculosis, and Roger was brought up by his mother and three aunts. The men of the family were mostly coalminers, one uncle being killed in a mining accident, but Roger avoided the pit by winning a place at the local grammar school, Swanwick Hall, and then an exhibition at New College, Oxford, to study mathematics.
At Oxford, he won a half-blue at badminton in addition to academic success. He gained his D Phil in theoretical physics from the university in 1952, for work on paramagnetism – in which materials take on magnetic properties in the presence of an external magnetic field, and lose them when the field is removed.
After graduation he was invited to spend a year at the University of California, Berkeley. He recalled that the prospect of absence in the US “concentrated the mind”, which led him back to Swanwick to marry Olga Atkinson, a close friend since schooldays. After their year away, they returned to Britain, where Roger joined the Atomic Energy Research Establishment, Harwell, Oxfordshire. He was appointed lecturer at Reading University in 1955, and after two years returned to Oxford University, where he was to spend the rest of his career.
At the end of his time as chief executive of OUP, he was president of the UK Publishers Association (1993-94). He was also active in many international bodies such as the International Council of Scientific Unions, where he had a special interest in the publication of research.
Among many honours, he won the Institute of Physics Maxwell Medal (with Kenneth Stevens) in 1968, was elected fellow of the Royal Society in 1976 and won the Society’s Guthrie Medal in 1990. He was knighted in 1987. Despite all these successes, Elliott remained fiercely proud of his Derbyshire origins. At a family dinner of Oxford Labour and Guardian-reading liberals, he proclaimed that he “was the only real working-class person present”.
He is survived by his daughter Rosalind, son, Martin, and two grandsons. His wife, Olga, and daughter Jane predeceased him.
• Roger James Elliott, physicist, born 8 December 1928; died 16 April 2018
