Geoffrey Dearnaley. 22 June 1930 — 5 May 2009

Geoffrey Dearnaley was distinguished for seminal contributions to the fields of low-energy nuclear physics, semiconductor detectors for nuclear radiations, and ion channelling at megaelectronvolt energies. Especially significant was his pioneering research on the ion implantation of semiconductor materials, ion implantation of metals, and ion-assisted coatings. He had a special skill in translating complex scientific concepts into industrially exploitable technologies, so his fundamental research contributions were taken up by industry in the automotive sector, electronics, and engineering. His innovations were seminal in the designs of several ion implantation systems, such as the Lintott implanter, that remained a major force in semiconductor implantation after many years. Later, he led the way with his second-generation ‘Blue Tank’ facility. It was his idea to improve the wear and oxidation resistance of metals by ion implantation, leading to successes as varied as improved resistance to high-temperature corrosion of nuclear fuel cladding and to notable reductions in wear of replacement hip joints. Geoffrey Dearnaley was a fundamental physicist who made significant original contributions to many scientific fields, and his understanding of both science and technology successfully showed industry how to exploit them.