John W. Cahn

from Wikipedia, the free encyclopedia
John W. Cahn, 2009

John Werner Cahn (born January 9, 1928 in Cologne ; † March 14, 2016 in Seattle , Washington ) was a German-American physical chemist and materials scientist who dealt in particular with thermodynamics in materials science.

Life

Cahn's father Felix Cahn was a respected advocate of the Jewish faith in Cologne. In 1933 he and his family fled from the National Socialists to the Netherlands, where Cahn went to school in Amsterdam. In the late 1930s they continued to flee to the United States, and Cahn attended Brooklyn Technical High School from 1941 to 1945 . In 1945 he became a US citizen.

Cahn studied chemistry at the University of Michigan (Bachelor 1949) and received his doctorate in physical chemistry ( The oxidation of isotopically labeled hydrazine ) from the University of California, Berkeley , under Richard E. Powell in 1953 . From 1952 to 1954 he was an instructor at the University of Chicago . He then went into research in chemical metallurgy in the Metallurgy and Ceramics Department Research Laboratory of General Electric in Schenectady under David Turnbull . In 1964 he became a professor of materials science (then metallurgy) at the Massachusetts Institute of Technology , where he stayed until 1978. He then worked at the National Institute of Standards and Technology (NIST) from 1977 , where he was a Senior NIST Fellow in the Material Science and Engineering Lab from 1984. Since 1984 he was a professor (affiliate professor) at the University of Washington . He lived in Seattle .

He was married to Anne Hessing since 1950 and has three children.

plant

Cahn dealt in particular with the thermodynamic description of phase phenomena in liquids and solids. For example, he treated the separation in two phases in spinodal decomposition , where the phase separation can be described relatively easily (Cahn-Hilliard equation with John E. Hilliard 1957), since it is a pure diffusion problem, in contrast to, for example, nucleation and nucleation (which Cahn also examined) where fluctuations play a role. He dealt with nucleation, crystal growth and the dynamics of crystal interfaces in melts. In 1977 he gave a simple, thermodynamic formulation of the wetting problem. In the early 1980s he played an important role in the early days of the quasicrystals theory . In 2002 he and Leonid Bendersky found evidence for the formation of an isotropic glass phase ( q-glass ) from a metal melt (made of iron, aluminum, silicon) with a first-order phase transition.

Cahn also dealt with the mathematical theory of phase boundaries and crystal formation, partly with Jean Taylor . With his doctoral student Francis Larché he developed a thermodynamic theory of solids under tension. With David W. Hoffman, he developed vector thermodynamics of interfaces in anisotropic media in 1972. With his doctoral student Sam Allen, he investigated phase transitions in iron alloys in 1975 (Allen-Cahn equation).

Honors and memberships

Cahn is a member of the National Academy of Sciences (1973), the American Institute of Metallurgical Engineers, the American Academy of Arts and Sciences (1975) and the National Academy of Engineering . In 1960/61 he was a Guggenheim Fellow (and visiting scholar at Cambridge University ). He holds honorary doctorates from Northwestern University and Université d'Evry .

Fonts

  • W. Craig Carter, William C. Johnson (Editor) The selected works of John W. Cahn , TMS (The Mineral, Metals and Materials Society), Warrendale, Pennsylvania
  • Cahn Adapting thermodynamics to materials science problems , The 1993 Hume-Rothery Award Lecture, J. of Phase Equilibria, Volume 15, 1994, pp. 373-379

Web links

Individual evidence

  1. ↑ Dates of birth can be found in the biography in his Selected Works
  2. ^ John W. Cahn, who fled Nazi Germany and became a foremost materials scientist, dies at 88
  3. You were already in the USA in 1937, but had to go back to the Netherlands because there were problems with your visa
  4. Life data, publications and academic family tree of John W. Cahn at academictree.org, accessed on January 23, 2018.
  5. ^ Cahn, W. Craig Carter, Jean Taylor Variational methods for microstructural evolution , NIST, section Cahn-Hilliard Equation
  6. ^ Hilliard, Cahn Free energy of a non uniform system I. Interfacial Free Energy , J. Chem. Phys., Volume 28, 1958, p. 258
  7. Cahn On spinodal decomposition in cubic crystals , Acta Met., Vol 10, 1962, p 179. Cahn spinodal decomposition , 1967 Institute of Metals Lecture, Trans. Met. Soc. ASME, Vol. 242, 1968, p. 168
  8. ^ Cahn, Hilliard On the nature of the interface between a solid metal and its melt , Acta Met., Volume 6, 1958, p. 772, Cahn Theory of crystal growth and interface motion in crystalline materials , Acta Met, Volume 8, 1960 , P. 554, Cahn Coherent fluctuations and nucleation in isotropic solids , Acta Met., Volume 10, 1962, p. 907, Cahn, WB Hillig, GW Sears The molecular mechanism of solidification , Acta Met., Volume 12, 1964, p 1421.
  9. ^ Cahn Critical Point Wetting , J. Chem. Phys., Volume 66, 1977, p. 3667. Moldover, Cahn An Interface Phase Transition: Complete to Partial Wetting, Science, Volume 207, 1980, p. 1073.
  10. ^ Dan Shechtman , I. Blech, D. Gratias, JW Cahn, A Metallic Phase with Long-Ranged Orientational Order and No Translational Symmetry, "Phys. Rev. Letters, Volume 53, 1984, p. 1951.
  11. ^ Cahn, Bendersky Formation of Glass by First Order Transition .
  12. ^ Cahn, Larché A Linear Theory of Thermochemical Equilibrium of Solids Under Stress, "Acta Met., Vol. 21, 1973, p. 1051.
  13. ^ Cahn, W. Craig Carter, Jean Taylor Variational methods for microstructural evolution , NIST, section Allen-Cahn equation .
  14. Acta Materialia Gold Medal ( Memento of the original from October 17, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.tms.org
  15. Heyn Denkmünze award winner ( Memento of the original dated February 5, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.dgm.de