Alexander received his DPhil in Engineering Science from Merton College, University of Oxford in 1995. He then held a Junior Research Fellowship at Fitzwilliam College, Cambridge. In 1999 he returned to Oxford to lead his own research group in the Department of Engineering Science, focusing on the study of materials structure and processes using optical, electron, ion, neutron and X-ray beams. He is now an Emeritus Professor of the Department.
He is Fellow of Trinity College and Fellow of the Institute of Physics, UK, and member of EPSRC peer review college. He is Senior Visiting Scientist at Diamond Light Source (UK synchrotron), where he has been named a 'leading light' for his contributions to UK X-ray science.
Alexander is Editor-in-Chief of Materials & Design, an open access Elsevier journal (2020 IF 6.289).