The thermal decomposition of erbium and lutetium oxalates

Abstract

The thermal decomposition behavior of erbium and lutetium oxalates was found to differ in many ways from that of the light rare earth group. On heating in vacuum at 300 deg C, the erbium and lutetium salts retained more than 25% of their water of crystallization. The last traces of water stabilizes the oxalates; decomposition in vacuum begins at 340 to 360 deg C, as with the light rare earth oxalates, but only after a long induction period. lnitially carbonates are formed, and the CO disproportionates only to a small extent, about 17% with erbium oxalate and about 6% with lutetium oxalate. The carbonates are unstable and decomposition to the oxides follows soon. This reaction has an unstabilizing effect on eventual oxalato-carbonate intermediates. The regularlties in the stabillty of the oxalates and in the disproportionation of CO, observed in the case of the light rare earths, are thus seen to extend also to the heavy rare earths. (P.C.H.)