By Paul A. Bartlett, Rollie J. Myers, and Andrew Streitwieser, Jr.
George Jura died after a short illness, from the effects of bladder cancer, on January 25, 1997. He was a friend to many and an outstanding teacher and research scientist. He was born in New York City on November 18, 1911, but his family soon moved to Chicago, where he received all of his schooling and did his first research work. He received the BS degree in 1939 from the Illinois Institute of Technology and the Ph.D. in physical chemistry in 1942 by the University of Chicago. During the next four years he was on the staff at Chicago. While there, he published 19 papers on surface and interface chemistry in collaboration with his mentor, William Draper Harkins. These publications established him as a leading research worker in what we now call classical surface chemistry.
In 1946, Wendell Latimer was changing the Chemistry Department in Berkeley from one that had been highly specialized to a more general department with emphasis on a variety of fields. Jura came to Latimer's attention and was brought to Berkeley as an Assistant Professor to help broaden its program in physical chemistry. It took several years for Jura to establish his laboratory in Lewis Hall, but by the start of the 1950s he was publishing papers in surface chemistry at his previous intensity. A number of these early Berkeley papers were published with other members of the department as collaborators . In these publications, he utilized the expertise of his fellow faculty members to strengthen his understanding of surface chemistry. This approach clearly illustrates the interactive nature of his research style, involving both graduate students and other faculty in the department. His second publication after he came to Berkeley was on the surface thermodynamics of MgO; this material has a face-centered cubic lattice that can be prepared with a large surface-to-volume ratio. Several years earlier, W. F. Giauque found that the heat capacity of finely powdered MgO was several percent higher than that of large single-crystal MgO. Jura made a guess at the surface area of Giauque's MgO and showed how this difference could be related to the thermodynamic properties of the surface. Later, he and a student made several heat-capacity measurements on a sample of powdered MgO, and they also measured the surface area of the 100 face of MgO to obtain the surface entropy, enthalpy, and tension as a function of temperature. In another pioneering effort, he and fellow faculty member George Pimental did spectroscopic work on molecules absorbed on surfaces. This type of work is very topical even today.
While this research was taking place, Jura took on the job of modernizing the undergraduate physical chemistry laboratory. Together with W. D. Gwinn, another new faculty member, they completely changed the required undergraduate laboratory course. Entirely new experiments were introduced, and the emphasis was placed on the students' independent thinking, not their ability simply to follow directions with pre-assembled apparatus. In some cases the students were given parts and had to assemble their own apparatus. This laboratory now uses more commercial instruments, but the available experiments still consist of many of those introduced by Jura.
In the late 1950s, Jura's research interests took a dramatic turn. He was always interested in the theory of solids, although his first work was done on surfaces, but while he was still in Chicago he decided to work on the effects of high pressure on solids. He was intrigued by the prediction of E. W. Bridgman, the pioneer in such work, that under pressure hydrogen would become a metal. At that time high-pressure work was rather expensive, requiring very large presses and tiny cells, all of which had to be fabricated. After he came to Berkeley, he found that the Atomic Energy Commission was eager to fund such work. Thus, Jura established a high-pressure laboratory within the Lawrence Radiation Laboratory facility immediately above campus. It occupied one of its small temporary buildings, and he found an engineer in the Radiation Laboratory, Harold Stromberg, to build a large press. His first paper on high-pressure work was reported in 1960 and published in 1961, and it showed how one could measure electrical conductivities for substances such as phosphorus and iodine up to 400,000 atmospheres.
Over the next few years, Jura, Stromberg, and several students developed multi-lead electrical measurements for metals under pressure. From the temperature dependence of the conductivities of Ytterbium and Bismuth at low temperatures and high pressures, Jura showed that they become small-gap nonmetals even at modest pressures. In another new technique, he and a student developed a method, using electrical pulses, for the measurement of the heat capacity of metals under pressure. He also made the first high-pressure spectroscopic measurements using the Mossbauer effect. These experiments showed that the high-pressure hcp phase of iron is not magnetically ordered and that the density dependence of the relevant exchange integral in iron and nickel does not match the simple Slater d-d overlap model. Using positron annihilation spectroscopy, he determined the pressure dependence of the Fermi surface of aluminum. His last high-pressure work was done on molecular solids. In collaboration with Mitchel Chen in Chemical Engineering, he measured the infrared spectra of polymers such as polyethylene. This work was the first detailed analysis of interchain coupling in this important polymer.
Although the presses that he and his students used became smaller with time, he never made the transition to diamond cells and their very small presses. However, his former students at other universities have made this transition and some of them are carrying on the traditions that Jura started in Berkeley. The last press used by him was moved into the undergraduate physical chemistry laboratory and is still being used today.
During his career he spent several periods visiting at the University of Arizona in Tucson. Both he and his wife, Rose, fell in love with the desert and South-Western Indian art. They collected even before it became so popular, and George had a collection of desert plants including 1,000 different cacti and agave. He is survived by his wife Rose and 3 sons, George, Michael (a Professor of Physics and Astronomy at UCLA), and Russell.