Thermal analysis of the evaporation and decomposition of rare-earth dipivaloylmethanates

The authors compared the behavior ML3 compounds when heated in air and under N2 at 0.1 MPa. It was conjectured that sublimation of ML3 in air, in contrast to vacuum or inert atmosphere, would be accompanied by the oxidation or decomposition of the thermodynamically least stable complexes. Derivatograms of NdI3 and ErI3 obtained in a N2 atmosphere and in air are shown. It was concluded that when rare-earth dipivaloylmethanates are heated in air, the degree of transfer of the complexes to the gas phase differs not only for elements of the cerium and yttrium subgroups, but also for elements that are adjacent in the series (neodymium and praseodymium, erbium, and holium). Thermal analysis can be used for comparative study of the properties of volatile rare-earth chelates