Since the 1940s, Oak Ridge National Laboratory has played a leading role in the development of ion beam technology and its application in materials processing and characterization. A key advance was made in the early 1960s when, in one of the first applications of computers in materials science, researchers predicted that positive ions (charged atoms) moving through a crystal would follow channels between the rows of atoms, thereby penetrating well into the crystal structure. The "ion channeling" effect became the basis for valuable scientific and commercial processes used to force ions into materials as a means of tailoring or altering their properties. One such process is ion implantation, now developed into a fine art that relies on accelerators to drive selected ions into materials at precise distances. Many materials so modified are now in routine use. Today, Oak Ridge operates a facility where the broader scientific community carries out fundamental research on various ion beam techniques to selectively design the near-surface properties of materials.

Scientific Impact: Ion beam techniques are widely used for research on topics such as superconductivity, thin-film electrolytes, quasicrystals, and surface structure and chemistry. The science continues to evolve; new approaches to controlling the morphology and properties of ion-implanted materials and layers now are being developed based on defect physics.

Social Impact: Ion implantation is used extensively in the electronics industry to "dope" semiconductors with special properties, both chemically and spatially. The process is also used to improve the wear resistance of titanium alloys in artificial prostheses for hip and knee replacements. By eliminating the need to rework failed replacement joints, this technology spares individuals from additional surgeries and saves as much as $100 million per year.

Reference: E. Chason, et al, "Ion beams in silicon processing and characterization," Journal of Applied Physics, vol. 81, no. 10, pp. 6513-6561 (1997) [Report of BES study panel]

A. Agarwal, H.-J. Gossmann, D. J. Eaglesham, S. B. Herner, A. T. Fiory, and T. E. Haynes, "Boron-enhanced diffusion of boron from ultra-low energy ion implantation," Applied Physics Letters vol. 74, pp. 2435-2437 (1999).

J. M. Williams and R. A. Buchanan, "Ion implantation of surgical Ti-6Al-4V alloy," Materials Science and Engineering vol. 69, pp. 237-246 (1985).

URL: http://www.ssd.ornl.gov/Org/Surfaces.html

Technical Contact: Don Freeburn, Office of Basic Energy Sciences, 301-903-3156

Press Contact: Jeff Sherwood, DOE Office of Public Affairs, 202-586-5806

SC-Funding Office: Office of Basic Energy Sciences