H. K. D. H. Bhadeshia

Plutonium is a strange metal with a rather low melting temperature of only 913 K. Like water, the first phase that forms during the solidification is less dense than the liquid. As a consequence, it undergoes a series of solid-state transformations which lead to densification. Many of these transformations occur by a martensitic mechanism. Almost all of these phases have low-symmetry crystal structures. Alloying elements such as aluminium are used to stabilise the face-centred cubic form.

The report below describes a model for estimating the lattice parameter of Pt-Al alloys as a function of concentration and temperature.

Crystal Structure of α-Plutonium

Crystal structure of alpha-plutonium
Crystal structure of alpha-plutonium
Crystal structure of alpha-plutonium
Crystal structure of alpha-plutonium
Crystal structure of alpha-plutonium

Crystal Structure of β-Plutonium

β-plutonium is monoclinic with space group I2/m and lattice parameters a=0.9284 nm, b=1.046 nm, c=7.859 nm, β=92.13° [W. H. Zachariasen and F. H. Ellinger, Acta Crystallographica, 16, 1963, 369].

The structure illustrated below is for pure β-plutonium, but the atoms are coloured differently to indicate the seven types present in the structure.

Crystal structure of beta-plutonium

Projection along [100]

Projection along [010]

Projection along [010] rotated by 180 degrees about [001]

Projection along [001]

Projection along [111]

Projection along [101]


Crystalmaker file for β-plutonium

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