James Byron Friauf (1896 1972) was an American

electrical engineer Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

who first determined the crystal structure of MgZn₂ in 1927. Friauf was a professor of physics at the Carnegie Institute of Technology, now

Carnegie Mellon University Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania. One of its predecessors was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools; it became the Carnegie Institute of Technology ...

. He had received training in the determination of the structure of crystals as a student at California Institute of Technology where he studied with

Roscoe Gilkey Dickinson Roscoe Gilkey Dickinson (May 3, 1894 – July 13, 1945) was an American chemist, known primarily for his work on X-ray crystallography. As professor of chemistry at the California Institute of Technology (Caltech), he was the doctoral advis ...

. The structure Friauf discovered consists of intra-penetrating

icosahedra In geometry, an icosahedron ( or ) is a polyhedron with 20 faces. The name comes and . The plural can be either "icosahedra" () or "icosahedrons". There are infinitely many non- similar shapes of icosahedra, some of them being more symmetrica ...

, which coordinate the Zn atoms, and 16-vertex polyhedra that coordinate the Mg atoms. The latter type of polyhedron is called a

Friauf polyhedron In geometry, the truncated tetrahedron is an Archimedean solid. It has 4 regular hexagonal faces, 4 equilateral triangle faces, 12 vertices and 18 edges (of two types). It can be constructed by truncation (geometry), truncating all 4 vertices of ...

and is, actually, an inter-penetrating tetrahedron and a 12-vertex truncated polyhedron. MgZn₂ is a member of the largest class of single intermetallic structures, since referred to as the

Laves phases Laves phases are intermetallic phases that have composition AB2 and are named for Fritz Laves who first described them. The phases are classified on the basis of geometry alone. While the problem of packing spheres of equal size has been well- ...

, the Friauf phases, or the Laves–Friauf phases.

Publications

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External links

Photo of James B. Friauf
from the Smithsonian collection, date unknown.

References

{{DEFAULTSORT:Friauf, James 1896 births 1972 deaths American electrical engineers Carnegie Mellon University faculty