Thermal decomposition of neodymium oxalate and changes in surface areas of the products

Abstract

The changes in surface area were studied when neodymium oxalate was heated in air in the range 30-950°C. The products at each stage were also examined by determination of mass loss, density, infra-red absorption, and by X-ray diffraction measurements. A plot of surface area vs. temperature of calcination showed two maxima; the first, near 400°C, was due to the decomposition and disintegration of the oxalate, followed by a fall in area due to sintering (surface diffusion and adhesion), and the second, near 700°C, to the decomposition and combustion of the carbonaceous materials dispersed in the solid matrix in the intermediate steps. These were followed by a fall due to sintering by lattice diffusion in the bulk solid.