UPt3

UPt₃ is an inorganic binary intermetallic crystalline compound of platinum and uranium.

Production

It can be synthesised in the following ways:

• as an intermetallic compound, by direct fusion of pure components according to stoichiometric calculations:

$\mathrm{𝟥}𝖯𝗍\mathsf{+}𝖴\stackrel{1700^{o}C}{\to }𝖴𝖯{𝗍}_{\mathrm{𝟥}}$

• by reduction of uranium dioxide with hydrogen in the presence of platinum:

$𝖴{𝖮}_{\mathrm{𝟤}}\mathsf{+}\mathrm{𝟤}{𝖧}_{\mathrm{𝟤}}\mathsf{+}\mathrm{𝟥}𝖯𝗍\stackrel{1700^{o}C}{\to }𝖴𝖯{𝗍}_{\mathrm{𝟥}}\mathsf{+}\mathrm{𝟤}{𝖧}_{\mathrm{𝟤}}𝖮$

Physical properties

UPt₃ forms crystals of hexagonal symmetry (some studies hypothesize a trigonal structure instead), space group P6₃/mmc, cell parameters a = 0.5766 nm and c = 0.4898 nm (c should be understood as distance from planes), with a structure similar to nisnite (Ni₃Sn) and MgCd₃.

The compound congruently melts at 1700 °C. The enthalpy of formation of the compound is -111 kJ/mol.

At temperatures below 1 K it becomes superconducting, thought to be due to the presence of heavy fermions (the uranium atoms).