Huffman , Donald Ray

(1935–) American physicist

Born at Fort Worth in Texas, Huffman was educated at Texas Agricultural and Mechanical College, at Rice University, Houston, and at the University of California, Riverside, where he completed his PhD in 1966. After spending a postdoctoral year at the University of Frankfurt, Huffman moved to the University of Arizona, Tucson, in 1967 and was later appointed professor of physics in 1975.

In 1985 in the laboratory of Richard Smalley a new form of carbon had been discovered: C₆₀, known asbuckminsterfullerene. The C₆₀ was produced by vaporizing a graphite target with a pulsed laser beam. The sooty carbon produced in this manner certainly contained a detectable amount of C₆₀, but all efforts to extract the substance from the residue in amounts sufficient to carry out a detailed spectroscopic study failed.

Huffman, in collaboration with Wolfgang Kratschmer of the Max Planck Institute for Physical Chemistry, Heidelberg, was involved in the discovery of the new forms of carbon known as fullerenes. For many years they had been interested in the nature of interstellar dust, which they believed to be mainly carbon. The interstellar matter has a characteristic broad absorption spectrum and Huffman and Kratschmer were experimenting with various forms of finely divided carbon produced in electric arcs. During this work, around 1982, they found a form of carbon with a peculiar double hump, which they called “the camel.”

When, in 1985, they heard of the discovery of C₆₀, buckminsterfullerene, they suspected that this might be the cause of their camel spectrum. Huffman and Kratschmer reproduced their earlier experimental conditions, in which they had formed a carbon powder by striking an arc between graphite electrodes in a low pressure of helium.

They treated the resulting soot with benzene, from which they crystallized a light-yellow solid, which they named fullerite. It was later found to contain about 75% of C₆₀ together with 25% of another fullerene, C₇₀. The method has allowed the production of fullerenes in large quantities.