Absolutely pure iron Five plates and two rods, National Art Gallery, Washington.
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Transcript of Absolutely pure iron Five plates and two rods, National Art Gallery, Washington.
Absolutely pure iron
Five plates and two rods, National Art Gallery, Washington
Smithsonian: Natural History Museum
Smithsonian: Air & Space
Fe-Ni alloy, 0.0021072 mm thick
Inter-galactic gas
guess what?
Fe
Entropy
P
P / 2
How pure can pure be?
o
o
A
B
A B
Gib
bs
free e
nerg
y p
er
mole
Concentration x of B
Incredibly difficult to get extreme purity!
hexagonal close-packed
hexagonal close-packed cubic close-packed
body-centred cubic
cubic close-packed
1.61.41.21.00.8-65
-55
-45
-35
Normalised volume
Diamond cubicCubic-P
Hexagonal-P
b.c.cc.c.ph.c.p
Coh
esiv
e en
ergy
(e
V/a
tom
)
Paxton et al. (1990)
pure ironpure iron
electron has a spin;
effectively a current in a loop, creating a little magnet;
this is the
Bohr magneton
Paramagnetic
Ferrimagnetic
Antiferromagnetic
Ferromagnetic
0 50 100 150 200
Pressure / kbar
800
400
0
γ
α ε
1200
1600δ
0 50 100 150 200
Pressure / kbar
800
400
0
γ
α ε
1200
1600δ Bundy (1965)
Iron atom in ferrite 2.2
Iron atom in thin film 3.1
Iron atom in austenite 2.8 or 0.6
Bhor magnetons
Fe
Ru
Os
Hs
Fe
Ru
Os
Hs
6d 2s
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- ???
H HO
body-centred cubic (ferrite)
cubic close-packed (austenite)
hexagonal close-packed
double hexagonal close-packed
trigonal
tetragonal
magnetic transitions
pure ironpure iron
DISPLACIVE
RECONSTRUCTIVE
The Song
an apple weighs 1 Newton
1 m
= 1 Pa
1201008060402000
2000
4000
6000
8000
10000
Fibre or Whisker Diameter / µm
Tensile Strength / MPa
"Scifer"
Whisker
1201008060402000
2000
4000
6000
8000
10000
Fibre or Whisker Diameter / µm
Tensile Strength / MPa
"Scifer"
Whisker
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
designby 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
Cooking temperature? 180 to 220 °C
Pizza steel, cooked at 200 °C for 20 days
Pizza steel, cooked at 200 °C for 20 days
2.5 billion apples on one square meter2.5 billion apples on one square meter
Caballero, Mateo & Bhadeshia
Longest (2 km) single-span bridge, near Kobe, Japan
Rope bridge, Atlantis, Bahamas
www.msm.cam.ac.uk/phase-trans/2001/pureiron.ppt
……/steel3.wav
