Obituary of Jamshed R. Patel

Prof. Jamshed (Jim) Ruttonshaw Patel, one of the pioneers in the development and application of modern synchrotron x-ray techniques in Materials Science, passed away on March 3, 2007 at his home in Menlo Park.

A native of India, he earned his Bachelors and Masters Degrees in Mechanical Engineering at the Massachusetts Institute of Technology (MIT) in 1949 and 1951, respectively, and completed a Sc.D. in Metallurgy, with the late Professor Morris Cohen, at the same institution three years later. His work at MIT led to his highly cited 1953 paper with Cohen on the effects of stress on the martensitic transformation in steels. He then worked as a senior engineer at the Sylvania Electric Co., Semiconductor Research, from 1953 to 1955, and was later a member of the research staff at the Raytheon Research Division, Waltham, Mass., from 1955 to 1961. At Raytheon, together with A.R. Chaudhuri, he conducted pioneering studies on the mechanical properties of silicon and germanium, measuring the velocities of dislocations in these materials with X-ray topography and providing the first evidence on the density of mobile dislocations in deforming crystals. He also worked on the first systematic X-ray study of the perfection of Czochralski-grown silicon, subjected to increasing degrees of surface damage from perfect (dynamical) to ideally imperfect (kinematic) scattering.

In 1961, he joined Bell Laboratories in the Materials Physics Division where he continued working on semiconducting materials, notably in collaboration with B.W. Batterman and P.E. Freeland. This work started a lifelong collaboration with Bob Batterman that continued to the present with work in Berkeley on x-ray microdiffraction. In the late 60s, Jim started a fruitful collaboration with the late Norio Kato (1923 - 2002) from Nagoya University who developed the dynamical theory of X-ray diffraction with spherical waves for undistorted and distorted crystals. Using the Pendellösung fringes observed by X-ray topography, they were able to apply the theory to solve complex diffraction problems in distorted crystals, such as obtaining the stress in an oxide layer deposited on a silicon substrate a crucial topic in the burgeoning semiconductor industry.

In 1971-1972, and again in 1984-1985, he was a visiting professor at the Laboratoire de Minéralogie and Cristallographie, Université Pierre et Marie Curie, Paris, France, where he taught a course on dynamical X-ray diffraction and dislocations in semiconductors. He published a series of papers with André Authier, on defects due to oxygen precipitation in silicon and characterization of stacking faults by X-ray topography.

In the 80s, he worked first with J.A. Golovchenko and then with J. Zegenhagen in pioneering studies to determine atomic positions at the surface of single crystal semiconductors, using the technique of x-ray standing waves, developed in the 60s, most notably by B.W. Batterman. Jim spent a year (1993-1994) as an Alexander-von-Humboldt Senior Scientist awardee at the München Universität, Germany, working on this project in the Institute of Prof. J.S. Peisl.

Retiring from Bell Laboratory, Jim moved to California in 1994 where he held a joint position at the Advanced Light Source (ALS) in Berkeley and SSRL/SLAC Stanford University. He was later appointed Consulting Professor in the Department of Materials Science and Engineering at Stanford. A Fellow of the American Physical Society, he also held numerous visiting and consultants positions at several science institutions such as the NSLS (Brookhaven), CHESS (Cornell) and Intel Corporation in Santa Clara. At the ALS, Jim was instrumental in the development of a successful sub-micron X-ray micro-diffraction program, obtaining the initial funding for the project though his position as a consultant for INTEL Corp. He initiated many materials science applications for the beamline, including the study of electromigration-induced plasticity in interconnect test structures, involving work with his graduate students at Stanford, and strain measurements at grain and domain boundaries in superconducting alloys. Jim worked tirelessly on the project providing scientific guidance to users and beamline personal until this past summer when he became ill and was restricted to his home in Menlo Park. Even then, he stayed active until his very last day, reviewing the work of his students, reading articles and working on a monograph for Springer on the technique and application of synchrotron x-ray microdiffraction.

Jim made major contributions throughout his long carrier in the field of X-ray diffraction topography of dislocations and stacking faults, X-ray Standing Waves, X-ray diffuse scattering associated with defects in ion-implanted silicon and synchrotron X-ray microdiffraction. He was an inspiration to all around him, a true gentleman of science, quiet and unassuming with the keenest of intellects, but always with the time to help and encourage his colleagues. He made a deep impression on anyone who knew him, and he will be sorely missed by all. Our thoughts go to his wife Eileen and his family and friends throughout the world.