David Barber, who was was born in 1935, passed away peacefully on Sept. 27, 2020, after a long battle with a rare disease.

He went to Bristol University on a state scholarship in 1953 to read Honors Physics and stayed until he completed a doctorate on dislocations, under the supervision of Jack Mitchell, FRS. Bristol University was one of the leading lights in the golden age of dislocations. On leaving Bristol, David worked for three years at Aluminium Laboratories, Banbury, before moving to Washington, D.C., to take up a position at the National Bureau of Standards, NBS (now NIST), where he studied the influence of defects on the mechanical properties of ceramics.

At NIST, he led the high-temperature ceramics group, who were studying materials of interest to the space program. He pioneered the use of transmission electron microscopy (TEM) to study microstructures in non-metals and, jointly with Nancy Tighe, was awarded the first medal given by the Electron Microscopy Society of America. He recognized that ion bombardment was a promising method for preparing thin samples of polycrystalline ceramics and resolved to apply it when, in 1965, he was “reverse brain drained” back to England and appointed a lecturer in the Physics Department of the newly created University of Essex.

There, he developed the ion milling method and researched its optimization. He actively promoted its use in materials science and geology as a means of applying TEM to study their problems, and he acted as a consultant to companies manufacturing early models of ion milling equipment. One of his papers about this technique was highlighted for its importance by the Science Citation Index.

On sabbatical leave from the University of Essex, at the University of California, Berkeley, in 1970, David discovered (jointly with P. Buford Price) cosmic ray tracks in samples returned from the first two Apollo missions. On returning to Essex, meteorites and rocks were added to the types of materials that his research group studied, and long-lasting collaborations developed with Robert Hutchison at the Natural History Museum, London, and Rudy Wenk at Berkeley.

Several study leaves were subsequently spent at Berkeley, and good use was made of the facilities at the National Centre for Electron Microscopy and those in Rudy Wenk’s laboratory. David and Rudy produced several papers on defect microstructures and behavior of carbonates and metamorphic carbonate rocks, which answered several long-standing questions in the geophysics of tectonics and are widely referenced. In addition, the two families became good friends, enjoying trips into northern California together, not least to Rudy’s small vineyard at Santa Rosa.

Successive promotions at Essex saw David become experimental chair professor by 1979, and in the next decade, he balanced his teaching and research roles with administrative duties as Dean (twice), Pro-Vice Chancellor, and Head of Department. Notwithstanding, various ground-breaking papers on the properties of diverse, nonmetallic materials and phenomena (ferroelectric, meteorites, and minerals) were published. He added insights into the nature of relaxor ferroelectrics, and also undertook some of the first investigations of ferroelectric thin films.

His meteorite work includes insights into the microstructural effects of shock deformation, the origins of some of the first Solar System solids, and the role of aqueous alteration in asteroids (including those that hitherto were assumed to be anhydrous). To further emphasize the diversity of David’s interests, he conducted a TEM study with Ian Freestone (British Museum) of the famous late Roman Lycergus Cup (https://en.wikipedia.org/wiki/Lycurgus_Cup) that finally yielded an explanation for its unique optical properties.

In 1991, David was granted an extended leave from the University of Essex, taking up linked positions as Physics Professor and Director of the Materials Characterization and Preparation Centre (MCPC) at the new Hong Kong University of Science and Technology (HKUST).  His scientific and administrative experience was invaluable in establishing the pattern of what quickly became an outstanding university, with the MCPC becoming a model for other scientific centres.

On his return to the UK in 1996, David took early retirement from the University of Essex but continued research, aided by visiting professorships at several UK universities, including Cranfield Institute of Technology, University of Greenwich, and Brunel University. Along with co-authored papers with a Physics group at the University of Minho, Braga, Portugal, on the properties of nanoparticles of semiconducting materials, his later work includes studies (with Ed Scott, Hawaii) of the Martial meteorite ALH80041, which showed that claims for evidence of biogenic activity on Mars were unfounded.

David was a visionary experimentalist, a brilliant and graceful mentor, and an enabling administrator, and as can be inferred from his scientific legacy, he had a broad, insightful intellectual curiosity. David will be fondly remembered and greatly missed by all his former graduate students, postdoctoral scholars, and colleagues in several countries around the world.

Clive Randall (Pennsylvania State University), Ian Reaney (University of Sheffield), Michael Reece (Queen Mary, University of London), Martin Lee (University of Glasgow), and Conel Alexander (Carnegie Institute for Science) .