William Francis Giauque

• Born: May 12, 1895
• Birthplace: Niagara Falls, Ontario, Canada
• Died: March 28, 1982
• Place of death: Oakland, California

Canadian American physical chemist

Giauque won the Nobel Prize in Chemistry in 1949 for his experiments with low-temperature substances, employing a new form of magnetic refrigeration called adiabatic demagnetization. With laboratory machines he helped design, Giauque achieved temperatures within one-tenth of a degree of absolute zero, confirmed the third law of thermodynamics, and discovered the oxygen isotopes of mass 17 and 18.

Primary fields: Chemistry; physics

Primary invention: Adiabatic demagnetization

Early Life

William Francis Giauque (jee-OHK) was born to William Tecumseh Sherman Giauque and Isabella Jane (Duncan) Giauque in the town of Niagara Falls, Ontario, Canada. William was the oldest of the Giauque’s three children. Because their parents were American citizens, William and his younger brother and sister were automatically American citizens as well. While William was still young, his family moved to Michigan, where his father, a skilled carpenter and mechanic, took employment as a weight master and station agent for the Michigan Central Railroad. William attended elementary school in Michigan until his father died in 1908, whereupon the family returned to Niagara Falls, Ontario.

To support the family, Giauque’s mother took a job as a part-time seamstress and tailor for Dr. John Woods Beckman, the son of a prominent Swedish parliamentarian and politician, who worked as a chemist for the American Cyanamid Company. Intending to help support the family, Giauque enrolled in the Niagara Falls Collegiate and Vocational Institute. His mother and Beckman persuaded Giauque to switch to the five-year college preparatory course. Graduating in 1913, Giauque worked for two years in the laboratory of the Hooker Electro-Chemical Company in Niagara Falls, New York. It was this laboratory work that sparked Giauque’s interest in chemical engineering.

By this time, Beckman had been transferred to Berkeley, California, and he suggested that Giauque continue his studies there. In 1916, Giauque enrolled in the University of California, Berkeley, which had a first-rate chemistry department and low tuition. In 1920, Giauque graduated summa cum laude with a B.S. degree in chemistry. An outstanding student, Giauque stayed on at Berkeley, studying as a university fellow in the 1920-1921 academic year and as a James M. Goewey Fellow in 1921-1922. Giauque also studied the application of quantum statistics to the calculation of thermodynamic quantities, which would prove crucial to his later research. Completing a dissertation on the behavior of matter at low temperatures under the supervision of the eminent chemists George Ernest Gibson and Gilbert N. Lewis, Giauque was awarded a Ph.D. in chemistry in 1922. He was immediately offered a position as an instructor in Berkeley’s chemistry department.

Life’s Work

Giauque would remain at the University of California, Berkeley, for the rest of his life, advancing to assistant professor in 1927, associate professor in 1930, and full professor in 1934. He would devote his career to the study of thermodynamics and cryogenics (how matter behaves at low temperatures), for which he would eventually earn a Nobel Prize. On July 19, 1932, he married Muriel Frances Ashley, a physicist and botanist; they had two sons, William Francis Ashley Giauque and Robert David Ashley Giauque.

The basis of Giauque’s life work was the study of entropy. Entropy is the state of disorder, or randomness, in a system of molecules. Walther Nernst, a German chemist, had postulated the third law of thermodynamics in 1906. Thermodynamics is the field of chemistry that studies the conversion of heat into energy. According to the third law of thermodynamics, deriving from the Nernst heat theorem, all perfect crystalline substances approach zero entropy as absolute zero temperature is approached. Thus, knowing the heat capacity of a substance at sufficiently low temperatures allows for the calculation of its absolute entropy. As Giauque explained in his December 17, 1949, Nobel lecture, it was the possibility of calculating this absolute entropy that interested him in low-temperature research. In his doctoral dissertation, Giauque had already found support for Nernst’s heat theorem with experiments on glycerol gas and crystalline glycerol.

In 1924, Giauque began developing a system of magnetic refrigeration that would allow for achieving the lowest temperatures yet recorded. This process would come to be called adiabatic demagnetization and was based on applying the third law of thermodynamics to the magnetic properties of certain molecules. (An adiabatic system is one in which heat is neither gained nor lost.) The theory of adiabatic demagnetization is complicated; in simple terms, it relies on the fact that certain paramagnetic compounds, such as gadolinium salt, have both thermal and magnetic entropy. At low temperatures, thermal motion disappears, but in these compounds magnetic entropy remains. Their molecules have internal magnetic fields that will line up with an external magnetic field. As the magnetic field is decreased through refrigeration, heat energy of the molecules is transformed into magnetic energy, further lowering the temperature.

Utilizing his adiabatic demagnetization theory, Giauque set out to develop machines in his low-energy laboratory to reach these low temperatures and thus confirm the third law of thermodynamics, that the entropy of a perfect crystal becomes zero at absolute zero temperature. In 1928, Giauque andHenrick Johnston obtained a low temperature of pure hydrogen through their new methods. In 1933, Giauque and his colleagues achieved a temperature of 0.25 kelvin. Another breakthrough came in 1929, when Giauque was focused on entropy calculations of oxygen based on its band spectra. After months of thinking through the problem, Giauque awoke one morning with the sudden illumination that the weak lines in the oxygen spectrum must be due to an isotope species. Giauque and Johnston set about calculating this data, leading to the discovery of isotopes of atomic weights 17 and 18 in the Earth’s atmosphere. This discovery proved that molecules retain zero-point vibrational energy at temperatures of absolute zero. It also led to revisions to the atomic weight scales, which would be incorporated in 1961. With the entry of the United States into World War II, Giauque made efforts to assist military research. He developed high-field electromagnets that could be used in military operations. He also directed an effort to build a mobile unit capable of producing liquid oxygen for use in medical operations and for rocket fuel.

In 1949, Giauque received the Nobel Prize in Chemistry for his research on the behavior of molecules at low temperatures. In the course of his career, he won numerous other prestigious awards, including Columbia University’s Charles Frederick Chandler Foundation Medal, the Franklin Institute’s Elliott Cresson Medal, the American Chemical Society’s Willard Gibbs Medal, and the Gilbert Newton Lewis Medal. In 1941, Giauque and P. F. Meads conducted a fruitful experiment to measure the heat content and entropy of aluminum and copper. Giauque was known as an extremely hard worker who relished his hours teaching students and conducting research in the laboratory. Over his career, he published 183 scientific papers and supervised fifty-one graduate students. He retired in 1981 and died in 1982.

Impact

Giauque’s contributions in the field of chemistry are numerous. His abiding interest was to bring substances to a state approaching absolute zero temperature, enabling him to study their properties of zero entropy in a relatively stable arrangement without the disorder to which they are normally subject. To accomplish this, Giauque made breakthroughs in the field of adiabatic demagnetization. In a certain sense, Giauque can be seen as following in the footsteps of such electromagnetic pioneers as Michael Faraday and William Sturgeon in conducting research employing solenoids and magnetic fields to test chemical properties. Most of the instruments necessary for such research were created by Giauque and his colleagues in their low-temperature laboratory at Berkeley. As a result of his research, improvements were made in the production of essential and industrial products such as glass, steel, and rubber. His experiments on the movements of molecules at zero entropy allowed for calculations of numerous chemical reactions. For these studies of the properties of matter at near-zero temperatures, he received the Nobel Prize in Chemistry.

Giauque’s research confirmed the theoretical work of some of the great theoretical physicists of modern times. Confirming Nernst’s third law of thermodynamics, Giauque answered several questions raised by Max Planck. Giauque’s study of the spectra of oxygen molecules, leading to the discovery of oxygen isotopes 17 and 18, confirmed Werner Heisenberg’s prediction that hydrogen and other elementary diatonic molecules could be in two different states, depending on how their molecular nuclei were oriented. Giauque’s low-temperature findings illustrated some of the thermodynamic theories of Lord Kelvin and also led to revisions in the table of standard atomic weights. Giauque’s work represents an impressive mix of theoretical and experimental chemistry, his ingenious invention of magnetic instruments allowing for important insights in thermodynamics and atomic physics.

Bibliography

Giauque, William. “Some Consequences of Low Temperature Research in Chemical Thermodynamics.” In Nobel Lectures: Chemistry, 1942-1962. New York: Elsevier, 1964. Giauque’s 1949 Nobel Prize lecture in which he describes his two major scientific achievements: reaching the lowest temperature through adiabatic demagnetization and discovering isotopes of atomic weights 17 and 18.

Jolly, William. From Retorts to Lasers: The Story of Chemistry at Berkeley. Berkeley: University of California Press, 1987. University publication with a chapter on Giauque as part of a history of the Berkeley chemistry department.

Pitzer, Kenneth, and David Shirley. “William Francis Giauque.” In Biographical Memoirs: National Academy of Sciences of the United States of America. Washington, D.C.: National Academy Press, 1996. A short biography emphasizing Giauque’s scientific accomplishments, with a list of his major papers.

Ventura, Guglielmo. The Art of Cryogenics: Low Temperature Experimental Techniques. Oxford: Elsevier Sciences, 2008. An illustrated technical treatment of modern cryogenic experiments, including Giauque’s adiabatic work in the 1920’s.

White, Guy, and Philip Meeson. Experimental Techniques in Low Temperature Physics. 4th ed. New York: Oxford University Press, 2002. A comprehensive history of modern experiments in refrigeration that gives an account of Giauque’s breakthrough in magnetic cooling.