Pasquarelli, Robert M.Robert M.PasquarelliWaleczek, MartinMartinWaleczekNielsch, KorneliusKorneliusNielschSchneider, Gerold A.Gerold A.SchneiderJanßen, RolfRolfJanßen2020-04-142020-04-142016-05-31Ceramic for Energy Conversion, Storage, and Distribution Systems (256): 177-186 (2016-05-31)http://hdl.handle.net/11420/5716Emerging applications of ordered, macroporous oxide photonic structures for thermal barrier coatings, structural coloration, and thermophotovoltaics requires the stability of these features at operating temperatures. However, in high-temperature environments (>1000 °C), these structures can exhibit significant undesired microstructural changes (phase changes, sintering, grain growth, etc.) that result in a loss of the desired properties. An approach for lowering the formation temperature of α-alumina in such structures was demonstrated by seeding with chromia by secondary infiltration from precursor solutions. Seeds of α-chromia, which formed at 500 °C, successfully lowered the α-alumina formation temperature from 1200 to 800 °C by heterogeneous nucleation. Upon heating to 1200 °C, these chromia-seeds went into solid-solution with the alumina structure. However, in contrast to unseeded structures, the resulting microstructures were prone to grain growth and loss of photonic properties upon heating at 1400 °C.enHeterogeneous nucleationPhotonic propertiesPhotonic structuresPrecursor solutionsα-aluminaα-chromiaBook Part10.1002/9781119234593.ch18Other