Tracy Hall

Howard Tracy Hall (October 20, 1919 – July 25, 2008) was an American physical chemist and the first person who grew a synthetic diamond by a reproducible, verifiable, and witnessed process, using a press of his own design.

Tracy Hall
Born
Howard Tracy Hall

(1919-10-20)October 20, 1919
Ogden, Utah, U.S.
DiedJuly 25, 2008(2008-07-25) (aged 88)
Provo, Utah, U.S.
Known forInventing the synthetic diamond

Early life

Howard Tracy Hall was born in Ogden, Utah in 1919. He often used the name H. Tracy Hall or, simply, Tracy Hall. He was a descendant of Mormon pioneers and grew up on a farm in Marriott, Utah. When still in the fourth grade, he announced his intention to work for General Electric. Hall attended Weber College for two years, and married Ida-Rose Langford in 1941. He went to the University of Utah in Salt Lake City, Utah, where he received his BSc in 1942 and his MSc in the following year. For the next two years, he served as an ensign in the U.S. Navy. Hall returned to the University of Utah in 1946, where he was Henry Eyring's first graduate student, and was awarded his PhD in physical chemistry in 1948. Two months later, he realized his childhood dream by starting work at the General Electric Research Laboratory in Schenectady, New York. He joined a team focused on synthetic diamond making, codenamed "Project Superpressure" headed by engineer Anthony Nerad.[1]

Invention of the synthetic diamond

As with many important inventions, the circumstances surrounding Hall's synthesis is the object of some controversy. It is undoubted that he produced synthetic diamond in a press of his own design[2] on December 16, 1954 and that he and others could repeat the process following Hall's procedure, a success which led to the creation of a major supermaterials industry. What is also undoubted is that Hall was one of a group of about a half dozen researchers who had focused on the achieving the synthesis for almost four years. These years had seen a succession of failed experiments, an increasingly impatient management, and a complex blend of sharing and rivalries among the researchers.[3]

Hall's success, in his telling of the story, came about because of his determination to go his own way with a radical redesign of the press, which employed a doughnut-shaped die surrounded by shrink-fit steel sleeves (the belt) which confined the sample chamber and two curved and tapered pistons which pressed on the sample chamber. He "bootlegged" the machining of the first hardened steel version of this press, which showed some promise, and eventually got management to approve the construction of it in the tougher, much more expensive Carboloy (tungsten carbide dispersed in cobalt, also known as Widia). However, his experiments were "relegated" (Hall claimed) to a smaller, antique, leaky 400 ton press, rather than a more expensive and new thousand ton press used by other members of the team.

The composition of the starting material in the sample chamber, catalyst for the reaction, and the required temperature and pressure were little more than guesses. Hall used iron sulfide and a form of powdered carbon as the starting material, with tantalum disks to conduct the electricity into the cell for heating it. The experiment was conducted at about 100,000 atmospheres, 1600 °C and took about 38 minutes.[4] Upon breaking open the sample, clusters of diamond octahedral crystals were found on the tantalum metal disks, which apparently acted as a catalyst.

GE went on to make a fortune with Hall's invention. GE rewarded Hall with a $10 savings bond.[5]

Later years

Hall left GE in 1955 and became a full professor of chemistry and Director of Research at Brigham Young University. At BYU, he invented the tetrahedral and Cubic press systems. He transferred the technology for the cubic press system to China in about 1960, and today the vast majority of the world's synthetic diamond powder is produced using the many thousands of cubic presses of Hall's design presently operating in that country. For many years, the first tetrahedral press was displayed in the Eyring Science center on campus at BYU. In the early 1960s, Hall invented the first form of polycrystalline diamond (PCD). He co-founded MegaDiamond in 1966, and later was involved with the founding of Novatek, both of Provo, Utah.

On Sunday, July 4, 1976, he became a bishop in The Church of Jesus Christ of Latter-day Saints and served five years. Later he served a church mission to southern Africa with his wife, Ida-Rose Langford. He died on July 25, 2008 in Provo, Utah at the age of 88. He had seven children, 35 grandchildren and 53 great-grandchildren.

Honors and awards

Patents

He was granted 19 patents in his career. Some especially notable ones were:

References
  1. "Tracy Hall, Leading Figure in Diamond Synthesis, Dies Aged 88". element six. Archived from the original on 2011-07-10. Retrieved 2009-05-05.
  2. H. T. Hall (1960). "Ultra-high pressure apparatus" (PDF). Rev. Sci. Instrum. 31 (2): 125. Bibcode:1960RScI...31..125H. doi:10.1063/1.1716907.
  3. H. T. Hall (1958). "Ultrahigh-Pressure Research: At ultrahigh pressures new and sometimes unexpected chemical and physical events occur" (PDF). Science. 128 (3322): 445–9. Bibcode:1958Sci...128..445H. doi:10.1126/science.128.3322.445. PMID 17834381.
  4. R. M. Hazen (1999). The diamond makers. Cambridge University Press. pp. 113, 125. ISBN 978-0-521-65474-6.
  5. Maugh II, Thomas H. (2008-07-31). "General Electric chemist invented process for making diamonds in lab". Los Angeles Times. Retrieved 2017-03-01.
  6. "Chemical Pioneer Award". American Institute of Chemists. Retrieved 30 November 2015.
  7. "Tracy Hall Science Center". Weber State University College of Science. Retrieved 23 January 2018.
  8. Kelly, Jeff (2014-01-16). "The Scientist Who Got $10 For A World-Changing Invention". KnowledgeNuts. Retrieved 9 June 2017.
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