Giauque , William Francis
(1895–1982) Canadian–American physical chemist
Born at Niagara Falls in Canada, Giauque spent his whole academic life at the University of California. He began as a student, obtaining his PhD in 1922, and was immediately appointed to the staff at Berkeley, becoming professor of chemistry in 1934.
Giauque was one of the pioneer workers in low-temperature phenomena. His early work in the 1920s concerned the experimental measurement of entropies at very low temperature – work that depended on the use of the third law of thermodynamics introduced in 1906 by Walther Nernst (the Nernst heat theorem). At the same time, Giauque used statistics to calculate the absolute entropies using the energy levels of molecules obtained from spectroscopy. This method, developed by Josiah Willard Gibbsand others, is known as statistical mechanics. Giauque's work provided support for the validity of both statistical thermodynamics and the third law.
Moreover, it led him to a method of attaining very low temperatures, close to absolute zero. The lowest temperature achieved at that time was 0.8K, reached by Heike Kamerlingh-Onnes in 1910 by pumping away the vapor of liquid helium and causing it to evaporate under reduced pressure. Giauque, and independently Peter Debye, proposed in 1925 a completely different method known as adiabatic demagnetization.
The basic idea is to take a paramagnetic substance surrounded by a coil of wire in a gas-filled container. The sample can be cooled by surrounding the container by liquid helium and magnetized by a current through the coil. It is thus possible to produce a magnetized specimen at liquid-helium temperature, and then to isolate it in a vacuum by removing the gas from the container. Within the magnetized specimen the ‘molecular magnets’ are all aligned. If the magnetic field on the specimen is reduced to zero the sample is demagnetized, and in this process the molecular magnets become random again. The entropy increases and work is done against the decreasing external field, causing a decrease in the temperature of the specimen.
There were considerable problems in putting this theory into practice, not least in measuring the temperatures produced. In 1933 Giauque had a working apparatus that improved on Kamerlingh-Onnes's in achieving a temperature of 0.1K. Giauque received the 1949 Nobel Prize for chemistry for his work on low-temperature phenomena.
He also worked on isotopes, showing in 1929 (with H.L. Johnson) that oxygen was a mixture of 16O, 17O, and 18O.

Scientists. . 2011.

Look at other dictionaries:

  • Giauque, William Francis — ▪ American chemist born May 12, 1895, Niagara Falls, Ont., Can. died March 28, 1982, Berkeley, Calif., U.S.       Canadian born American physical chemist and winner of the Nobel Prize for Chemistry in 1949 for his studies of the properties of… …   Universalium

  • Giauque, William Francis — ► (1895 1982) Químico estadounidense. Fue premio Nobel de Química en 1949, por sus trabajos sobre los isótopos y las bajas temperaturas …   Enciclopedia Universal

  • William Francis Giauque — Nacimiento 12 de mayo de 1895 …   Wikipedia Español

  • William Francis Giauque — (* 12. Mai 1895 in Niagara Falls/Kanada; † 28. März 1982 in Berkeley) war ein amerikanischer Chemiker. Giauque erhielt 1949 den Nobelpreis für Chemie für seinen Beitrag zur chemischen Thermodynamik, insbesondere für seine Untersuchungen über die… …   Deutsch Wikipedia

  • William Francis Giauque — (12 mai 1895 à Niagara Falls, Ontario, Canada – 28 mars 1982 à Berkeley, Californie, E. U.) est un ingénieur chimiste américain d origine canadienne. Il a reçu le prix Nobel de chimie en 1949 « pour ses contributions dans le champ de la… …   Wikipédia en Français

  • William Francis Giauque — Nació el 12 de mayo de 1895 y falleció el 28 de marzo de 1982 Ganador del premio Nobel de química en 1949 por sus estudios sobre las características que presenta la materia a temperaturas cercanas al cero absoluto. Guillermo Francis Giauque nació …   Enciclopedia Universal

  • Chemienobelpreis 1949: William Francis Giauque —   Der amerikanische Chemiker wurde für seine Arbeiten auf dem Gebiet der chemischen Thermodynamik, insbesondere die Eigenschaften von Substanzen bei extrem tiefen Temperaturen betreffend, geehrt.    Biografie   William Francis Giauque, * Niagara… …   Universal-Lexikon

  • Giauque — Giauque, William Francis …   Enciclopedia Universal

  • William F. Giauque — William Francis Giauque William Francis Giauque (12 mai 1895 – 28 mars 1982) a remporté le Prix Nobel de chimie en 1949 pour son travail sur les propriétés de la matière à des températures proches du zéro absolu. Vie Il est né à Niagara Falls, en …   Wikipédia en Français

  • William Giauque — William Francis Giauque William Francis Giauque (12 mai 1895 – 28 mars 1982) a remporté le Prix Nobel de chimie en 1949 pour son travail sur les propriétés de la matière à des températures proches du zéro absolu. Vie Il est né à Niagara Falls, en …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”