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Absolutely pure iron. Five plates and two rods, National Art Gallery, Washington. Smithsonian: Natural History Museum. Fe-Ni alloy, 0.0021072 mm thick. Smithsonian: Air & Space. Inter-galactic gas. Fe. guess what?. How pure can pure be?. Entropy. P. P / 2. o. m. B. o. m. A.
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Fe-Ni alloy, 0.0021072 mm thick Smithsonian: Air & Space
Inter-galactic gas Fe guess what?
How pure can pure be? Entropy P P / 2
o m B o m A Gibbs free energy per mole Incredibly difficult to get extreme purity! A B Concentration x of B
hexagonal close-packed cubic close-packed
body-centred cubic cubic close-packed
-35 -45 -55 -65 pure iron Cubic-P Diamond cubic Cohesive energy (eV/atom) Hexagonal-P b.c.c c.c.p h.c.p 0.8 1.0 1.2 1.4 1.6 Normalised volume Paxton et al. (1990)
electron has a spin; effectively a current in a loop, creating a little magnet; this is the Bohr magneton
Bhor magnetons Iron atom in ferrite 2.2 Iron atom in thin film 3.1 Iron atom in austenite 2.8 or 0.6
Fe Ru 6d 2s Os Hs
Iron [Ar] + 8 e- b.c.c Ruthenium [Kr] + 8 e- h.c.p Osmium [Xe] + 14f + 8 e- h.c.p Hassium [Rn] + 14f + 8 e- ???
body-centred cubic (ferrite) cubic close-packed (austenite) hexagonal close-packed double hexagonal close-packed trigonal tetragonal magnetic transitions pure iron
DISPLACIVE RECONSTRUCTIVE
an apple weighs 1 Newton = 1 Pa 1 m
1 Denier: weight in grams, of 9 km of fibre 10 Denier Scifer is 9 Denier
Scifer, 5.5 GPa with ductility! Kobe Steel
Atom probe image of Scifer, 5.5 GPa steel wire Bhadeshia and Harada, 1993
TRANSPARENT STEEL:the teaching of creative design by Harry Bhadeshia Materials World, March 1995, p. 128
Why is iron opaque? opaque transparent
1991 Sumio Iijima studied soot, found nanotubes, nested like Russian dolls. Nanotubes grow efficiently from gas with iron as catalyst.
Perception of smell template model spectroscopic model Luca Turin
nickel in cage molecule iron in cage molecule Luca Turin
180 to 220 °C Cooking temperature?
Pizza steel, cooked at 200 °C for 20 days 2.5 billion apples on one square meter Caballero, Mateo & Bhadeshia
www.msm.cam.ac.uk/phase-trans/2001/pureiron.ppt ……/steel3.wav