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