Synthesis and thermal decomposition of rare earth isovalerates and their solutions with amines as an effective pathway to obtain oxide nanomaterials

Abstract

Rare earth (RE) carboxylates are considered as effective metal-organic precursors (MOPs) for chemical preparation of RE oxide nanomaterials via thermal decomposition. However RE oxocarbonates being the intermediate products of this process require high temperature treatment to be decomposed, that complicates the application of mentioned MOPs for preparation of nanomaterials. Here we report synthesis, composition and thermal behavior of four rare earth (La, Gd, Y, Lu) isovalerates. Novel compounds were studied by single crystal and powder XRD, TG-DTA, FTIR and DFT calculations. Thermal decomposition of RE isovalerates and metal-organic precursors based on the RE isovalerate – isopropanol – amine (monoethanolamine or diethylenetriamine) systems was thoroughly studied. The effect of amines, decomposition atmosphere (air or argon) and nature of RE ion on thermal behavior was discussed. The developed MOPs decompose to RE oxides below 700 °C which allows them to be used for deposition of high-quality Y2O3 and LaLuO3 thin films by MOCSD process.