Professor Arthur J. Freeman
Arthur J. Freeman died on June 7, 2016. Freeman was a Professor Emeritus in the Department of Physics and Astronomy at Northwestern University, Evanston, IL. He wasapioneering developer of computational quantum material science based on density functional theory to simulate new materials via virtual fab within high-performance computers.
Art Freeman was born in Lublin, Poland on February 6, 1930. He came to the U.S. at age 7 with his three siblings, who all predeceased him. Art received his Ph.D. in Physics at MIT in 1956 under the direction of John C. Slater. The title of Art's thesis was The Electronic Energy of the OH Molecule. Art then was affiliated with the MIT Magnet Lab from 1962-1967, becoming its associate director before coming to Northwestern University. He was a Guggenheim Fellow, a Fulbright Fellow, an Alexander von Humboldt Fellow, and the first MRS Medalist, with the citation, "In recognition of his pioneering achievements in the field of monolayer and low dimensional magnetism." He was also the first recipient of the IUPAP Magnetism Award and Néel Medal. Art was a Fellow of the APS and the AAAS, and founding Editor in Chief of the Journal of Magnetism and Magnetic Materials.
Art Freeman and his coworkers made seminal contributions to a fundamental school of thought in condensed matter physics known as predictive atomistic theory of real solids, the historical continuation of the works of Enrico Fermi, John Slater, Walter Kohn, and Marvin Cohen among others. The approach is based on an "input" of chemical identity of the constituent atoms and their structure, and provides as "output" predictions of the material's properties. The Hamiltonian characteristically includes the elementary interactions that setup the interatomic "glue," and its solution provides the basic constants for the specific system at hand, such as forces (for geometry optimization and calculation of mechanics); force-constants (for lattice dynamics calculations); spin-spin-interactions (for Heisenberg-based magnetism calculations); or atom-atom pair interactions (for Ising-based temperature-composition phase diagram calculations), with the number and range of interactions decided by the underlying Hamiltonian, not by the user. The basic insight, as distilled from biology and chemistry, is that structure and composition define the platform for understanding physical properties and functionality. Specific achievements of Freeman and his associates include:
- • the development of the most accurate realization of the density functional approach. Their all-electron, full potential, linearized augmented plane-wave (FLAPW) technique allows for a full range of interactions, such as exchange (including screened exchange), spin-spin (including nucleon spin), spin-orbit, and electron-photon (including x-rays). Art is the father of the FLAPW method, a research tool now applied worldwide for studies of the structural, electronic, magnetic, optical (linear and non-linear) and mechanical properties of metals, semiconductors, insulators and nanostructures;
- • approaches that consistently initiated paradigm changes, as in shattering the belief in the free-electron model of rare-earth optical and electronic properties in the 1960's, and ushering in the modern transition-metal viewpoint. They redefined our understanding of the nature of the light actinide metals in terms of f-bands rather than localized levels. They explained the seminal issue of the counterintuitive sign of the hyperfine interaction measured in Mössbauer spectroscopy as arising from the core polarization. Their predictions of enhanced magnetic moments at surfaces and interfaces inspired widespread searches for new magnetic surface phenomena and debunked belief in magnetic dead layers. Their treatment of surface magnetic anisotropy set new standards in the 1990's. Their work on oxide superconductors highlighted the importance of the layering of metallic and insulating planes in controlling the normal-state electronic properties.
ISI lists over one thousand publications co-authored by Freeman and over 37,000 citations (h = 92) making Freeman one of the top twenty most-cited physics researchers worldwide.
Art Freeman was an international ambassador of science. He trained and mentored more than 50 visiting scholars, postdocs and graduate students from Asia (particularly Japan, China and Korea) and European countries. Many of them have become leaders in their home countries and have made significant contributions in computational materials science, physics and chemistry.
Art will be remembered as a prolific scientist of great drive and insight, as a devoted husband, father, and stepfather, and as a warm and caring person by his students and associates the world over. For the last twenty-five years he was the beloved husband of Doris Caro-Freeman, presently of Brookline, MA. He is also survived by two of his four children, Seth Freeman and Sarah Packer, four grandchildren, and two stepchildren, Physics Professor Jeff Grossman of MIT and Anne Grossman-Bernheimer, and six step-grandchildren.
