Reimanis, Ivar E. (Ivar Edmund)Billman, Julia E.2023-10-302023-10-302023https://hdl.handle.net/11124/178511Includes bibliographical references.2023 Spring.CuCr2O4 is a promising spectrally selective material for solar receiver coatings to improve solar efficiency. Key requirements of such a coating are its high absorptivity, robustness, and ability to prevent high temperature oxidation of the substrate. This work describes synthesis routes for the creation of CuCr2O4 particles that exhibit adequate sinterability for developing robust solar receiver coatings that can prevent oxidation. The Pechini and modified Pechini sol-gel methods were directly compared as two routes for nanoparticle creation. Particle growth was studied by heating the nanoparticles at different temperatures (650°C, 750°C, 850°C) and times (between 1 h and 24 h) and measuring the particle sizes via laser diffraction and scanning electron microscopy. Phase identification was determined by powder X-ray diffraction. The kinetics of particle growth observed were consistent with a diffusion limited inhibited grain growth mechanism. The sol-gel route synthesized through modified Pechini and calcined at 650°C for 3h produced the smallest (84nm) single-phase spinel particles. The modified Pechini method displayed evidence of greater agglomeration and produced smaller particles than the Pechini method. Pellets were formed to evaluate the effectiveness of the sol-gel derived nanoparticles for improving sinterability. It was demonstrated that CuCr2O4 powders of larger starting particle sizes exhibit low sinterability and do not form coatings capable of preventing high temperature oxidation of the underlying substrates.born digitalmasters thesesengCopyright of the original work is retained by the author.agglomerationcopper chromiteparticle growthPechinisol-gelText2023-10-18