Obituary: Professor Bryan Coles

Bryan Coles made important contributions to our knowledge and understanding of metals and alloys and worked unstintingly for Imperial College, London, as Professor of Solid State Physics (1966-91), Dean of the Royal College of Science (1984-86) and Pro-Rector (1986-91).

He was born and educated in Cardiff, graduating from the University of Wales with first class honours in Metallurgy in 1947. As a research student in Oxford he expressed a desire to work on the physical rather than the structural properties of alloys. Coles liked to tell how he was gently admonished by his supervisor, the distinguished metallurgist William Hume- Rothery, with the words "We must leave that sort of thing to the Clarendon".

However, Coles persisted and Hume-Rothery recommended him to Sir George Thomson at Imperial College, who appointed him Lecturer in Metal Physics in 1950. This was the beginning of experimental solid state physics at Imperial, although theoretical work in the subject was already strongly established in the mathematics department under the leadership of Harry Jones.

Coles built up an extremely successful research group and rose steadily through the academic ranks. His inaugural lecture as Professor of Solid State Physics had the deliberately ambiguous title "Solid State Physics - in particular metals", thus revealing his fascination with the individual properties of different metals.

His most important work was concerned with the varied behaviour of impurity atoms carrying magnetic moments when introduced into different non-magnetic metals. At low temperature the magnetic moments may be quenched, the so- called Kondo effect, or may freeze into a complex state which Coles called a spin glass. Both phenomena turned out to have deep theoretical ramifications and Coles initiated theoretical solid state physics within the Physics Department with several brilliant appointments.

Coles and his group were at the forefront of developments in this area of physics for several decades. Another strand in Coles's work was his continuous enthusiasm for superconductivity, even when most people thought that new developments in this field were unlikely. Following the dramatic discovery of high-temperature superconductors in 1986, David Caplin, a long-standing member of Coles's group, was well poised to establish the College Centre for High Temperature Superconductivity, which co-ordinates work in several departments at Imperial College.

Coles led his research group by inspiration and example. Its members developed as individuals and created their own networks of students, research associates and international collaborators. Coles was the antithesis of the professor whose name appears on every publication of his group, regardless of whether he himself contributed.

Coles's contacts spanned five continents but he was always drawn to the United States. His most extended visit there was as a Research Fellow at the Carnegie Institute of Technology in Pittsburgh from 1954 to 1956. This had a decisive influence on his life, not least because he met, and married in 1955, Merivan Robinson, a graduate of the University of Minnesota. Later, it was regular visits to Los Alamos National Laboratory which sustained his research activity during his predominantly administrative years as Pro-Rector.

It was a surprise to many when Coles agreed to become Pro-Rector of Imperial in 1986. Typically such a position would be regarded as a stepping-stone to a vice-chancellorship but Coles, with his devotion to research, had no such ambition. He brought to the post an unswerving loyalty to the college and a sense of justice and fair play. While not shrinking from controversy he was adept at mediating between rival factions. His broad cultural interests found expression in his support for the Department of Humanities and in forging links with the neighbouring Royal College of Music.

Coles served on many councils and committees, of the Science Research Council, Institute of Physics, European Physical Society and other bodies, frequently in the arduous position of chairman. He had a long involvement with the scientific publishers Taylor and Francis, both as editor of the journal Advances in Physics for many years and as chairman of their board from 1976. He was also chairman of two Royal Society committees after his election to a Fellowship in 1991. This last honour was believed by many to be long overdue.

After his official retirement in 1991 Coles, as Emeritus Professor and Senior Research Fellow, enjoyed an Indian summer in his research. While still based at Imperial College he travelled widely. During the Eighties new "heavy fermion" compounds had been discovered in which current-carrying electrons are disguised as particles with a thousand times their normal mass. Coles delighted in this new field, which combined his interests in superconductivity and the Kondo effect. He collaborated in making interesting studies of these systems by combining his favourite simple technique of measuring electrical resistivity with the more sophisticated techniques of neutron scattering and muon spin resonance. He was planning new experiments at Imperial just three days before his death.

Bryan Coles was a conversationalist and a raconteur, with a deep interest in the theatre and music. He could always produce an apt quotation, frequently from Shakespeare but sometimes in Latin, to the consternation of his colleagues. He was driven by his love for his subject. He had a wonderfully generous nature and brought the same love and care that he lavished on physics to his relationships with friends, students and colleagues.

Bryan Randell Coles, physicist: born Cardiff 9 June 1926; Lecturer in Metal Physics, Imperial College, London 1950-59, Senior Lecturer in Physics 1959-62, Reader in Physics 1962-66, Professor of Solid State Physics 1966- 91 (Emeritus), Pro-Rector 1986-91, Senior Research Fellow 1991-97; Dean, Royal College of Science 1984-86; FRS 1991; married 1955 Merivan Robinson (two sons); died London 24 February 1997.