Ian Baker obtained his B.A. and D. Phil. in Metallurgy and Science of Materials from the University of Oxford. He joined the Faculty of the Thayer School of Engineering at Dartmouth College, in 1982, where he is currently the Sherman Fairchild Professor of Engineering and Senior Associate Dean for Academic Affairs.
He was the Director of the NIST-funded Center for Nanomaterials Research at Dartmouth from 2002-2005 and the Director of the NIH-funded Dartmouth Center for Cancer Nanotechnology Excellence from 2010-2016. He is a Chartered Engineer (U.K.) and a Fellow of ASM International, The Minerals, Metals and Materials Society, The Institute of Materials, Minerals and Mining (U.K.), the Materials Research Society, and the American Association for the Advancement of Science. He is Editor-in-Chief of Materials Characterization, has published around 400 papers and has given over 300 presentations at conferences, universities and to industry.
Research interests include: mechanical behavior, including wear and fracture of metals, intermetallic compounds and ice; processing and recrystallization phenomena, particularly the effect of particles on recrystallization and processing by directional recrystallization; applications of electron microscopy, X-ray diffraction and X - ray topography, particularly in-situ deformation experiments; the structure, chemistry and properties of snow, firn and ice cores; production and properties of nanocrystalline, particularly magnetic, materials; nanoparticles for biomedical applications.
STRAIN-INDUCED ferromagnetism in INTERMETALLIC compounds
It has been known for over forty years that B2-structured FeAl can undergo a paramagnetic to ferromagnetic transition upon cold working. Strain-induced ferromagnetism (SIF) in FeAl arises from the generation of APB tubes, where Fe atoms can have ≥3 like nearest neighbors. The resulting saturation magnetization, Ms, depends on both the Fe:Al ratio, the presence of substitional alloying elements and the degree of deformation.
This presentation will outline a quantitative model that describes the effects of these parameters in terms of the local environment theory applied to the atoms in APB tubes. SIF in the L21-structured compound Fe2AlMn will also be outlined and explained by considering the site preferences of ternary atoms on the Fe and Al sublattices. The value of Ms depends on whether this compound is in the B2 or L21 state, and can show values up to 96 emu/g - by comparison pure nickel is 59 emu/g. TEM observations of APB tubes in lightly-strained single crystals of FeAl and Fe2AlMn will be presented, and the annealing out of APB tubes and the associated activation energy will be discussed. The effects of plastic strain on the magnetic properties of some strongly-ordered L12 intermetallics will also be briefly outlined.