Abstract
Nanostructured neodymium titanium oxide thin films and powders with different phase compositions were produced by a straightforward particulate sol-gel route. The sols showed a narrow particle size distribution in the range of 20-26 nm. X-ray diffractograms (XRD) show that the powders contain mixtures of Nd4Ti9O24, Nd2Ti4O11, Nd3Ti4O12 for titanium dominant powders (Nd:Ti≤45:60), mixtures of Nd2TiO5 and Nd2O3 for neodymium dominant powders (Nd:Ti≥75:25) and pure Nd3Ti4O12 phase for equal molar ratio of Nd:Ti. Transmission electron microscope (TEM) images confirmed that the average crystallite size of the powders annealed at 400ºC was in the range 1.0-2.8 nm and a gradual increase was occurred up to 6.7 nm by heat treatment at 1000ºC. Field emission scanning electron microscope (FE-SEM) analysis revealed that the deposited thin films had uniform and nanocrystalline structure. Moreover, atomic force microscope (AFM) images presented that the thin films had a columnar like morphology with average grain size in the range 17-30 nm at 600ºC and 40-60 nm at 800ºC. The surface area of the powders was enhanced by increasing Nd:Ti molar ratio and reached as high as 110 m2/g for the powder containing Nd:Ti=75:25 (molar ratio) at 400ºC.
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