The theoretical condensed-matter physicist Marshall Stoneham died earlier today at the age of 70. Stoneham, who was a fellow of the Royal Society, spent much of his career studying the effects of defects in solids and published several books on the topic. In October 2010 he took over as president of the Institute of Physics, which publishes physicsworld.com. His duties for the Institute will for the moment be taken over by the Institute's immediate past-president Jocelyn Bell Burnell.

Stoneham was born in Barrow-in-Furness on 18 May 1940. He completed a PhD in physics at the University of Bristol in 1965 and spent much of his career at the UK Atomic Energy Research Establishment (AERE) in Harwell, Oxfordshire, where he led the solid-state and quantum-physics group of the theoretical division between 1974 and 1989. The following year he was appointed director of research at AEA Industrial Technology and later took up the position of chief scientist of AEA Technology.

In 1995 Stoneham moved to University College London, where he became director of the university's interdepartmental Centre for Materials Research. With his wife Doreen, who is also a physicist, Stoneham founded Oxford Authentication Ltd in 1997 and remained a director at the time of his death. The small firm uses thermoluminescence techniques to establish the provenance of earthenware, stoneware, porcelain and the casting cores of bronzes.

Stoneham also served as vice-president of IOP Publishing, the publishing arm of the Institute, and was editor-in-chief of the Institute's Journal of Physics: Condensed Matter. In his spare time, Stoneham was an enthusiastic French horn player and even published two books in this area. He is survived by his wife Doreen and two daughters. In a statement, the Institute said that "he will be greatly missed by the physics community, and by all of us in the Institute".

Stoneham had a wide range of research interests, including the electronic structure of defects, the properties of surfaces and interfaces, the true nature of scanning-probe microscopy and diamond films. However, in recent years he had taken a growing interest in quantum-information technology and hoped to create solid-state quantum gates that are compatible with silicon and could operate at room temperature. Stoneham was also involved in various projects linking physics and medicine, including one that sought to understand how humans can discriminate between different scents and whether left- and right-handed versions of chiral molecules should smell the same or not.