James Bentley
This year’s recipient of the MAS Peter Duncumb Award for Excellence in Microanalysis, Jim Bentley is a consultant with Microscopy and Microanalytical Sciences, Oak Ridge, Tennessee. He was born and grew up in Tipton, Staffordshire, England in the heart of what is known as the Black Country. He attended Tipton Grammar School and following a B.Sc. in Physics (1970) from Salford University and a M.Sc. in Physics of Solids (1971) from Birmingham University, he received a Ph.D. in Physical Metallurgy and Science of Materials (1974), also from Birmingham University, for transmission electron microscopy (TEM) of neutron-irradiated molybdenum. He was a research staff member in the Metals and Ceramics (later Materials Science and Technology) Division of Oak Ridge National Laboratory (ORNL) from 1974 to 2010, serving periods as task leader and group leader.
Most of Jim’s career has involved wide-ranging applications of analytical transmission electron microscopy (AEM) in materials science. At ORNL, he initially worked on TEM of neutron irradiated V and Mo alloys, but soon became involved in fledgling AEM, especially instrumental modifications to help mitigate the hole count and improve X-ray energy-dispersive spectroscopy (EDS) of precipitates and segregation in stainless steels and other alloys. Jim eagerly adopted electron energy-loss spectroscopy (EELS), using core-loss intensities to measure compositions. He developed log-polynomial EELS background fitting to enable quantitative analysis of transition metal borides.
In the early 1980s, as group leader, Jim greatly expanded the collaborative research efforts of ORNL’s Shared Research Equipment (SHaRE) Program and established an effort on atom probe field ion microscopy (APFIM) with a view to developing 3D atom probe analysis, now known as atom probe tomography (APT). SHaRE and APT remain important activities at ORNL nearly 30 years later. In the mid-to-late 1990s, Jim established two new tools for compositional mapping that became core capabilities of the SHaRE facility – energy-filtered TEM (EFTEM) and simultaneous EDS and EELS spectrum imaging with a FEG-(S)TEM. Quantitative composition mapping with core-loss EFTEM had few practitioners in the mid-1990s but Jim successfully applied it to interfaces in metals, ceramics, and semiconductors by selecting optimum acquisition parameters and developing new procedures such as the 4-window method to deal with overlapping edges such as O-K and Cr-L23. His most extensive applications of EFTEM elemental mapping have been to thin-film magnetic recording media for computer hard disks and to nanoclusters in nanostructured ferritic alloys.
Jim also made significant contributions with EFTEM plasmon imaging and valence-state mapping, site occupancies in intermetallic alloys by ALCHEMI with corrections for ionization delocalization, reflection-mode imaging and analysis (REM and REELS), including high-temperature in-situ annealing of ceramics, and HAADF STEM imaging of metallic nanoparticles.
Jim received the1975 Thomas Turner Medal from Birmingham University, two ORNL Technical Achievement Awards, and five MSA poster awards. Jim served as MSA Awards Committee Chair and as MSA Program Chair for the hugely successful fiftieth-anniversary meeting in Boston in 1992. He became an (inaugural) MSA Fellow in 2009. Jim has served as a MAS Tour Speaker (2000-2001) and MAS Director (2009-2011). He is well known for mentoring numerous students and postdocs, especially through SHaRE collaborative research.