Nanocrystalline yttria-doped ceria powder, with the composition Ce0.55Y0.45O1.775, was synthesized by a combustion technique using citric acid as the fuel and the corresponding metal nitrates as oxidants. This process involves mild conditions as the external temperature required to initiate the combustion is only approximately 250 °C. The product was characterized by x-ray diffraction (XRD) to ascertain the phase purity. The crystallite size of these calcined samples, as seen by transmission electron microscopy, was found to be in the range 6 nm to 50 nm. The surface area of the fine powder, as obtained from the Brunauer–Emmett–Teller technique, was about 140 m2/g. The agglomeration behavior as a function of temperature and the lattice thermal expansion studies were carried out using high-temperature XRD. This nanocrystalline powder resulted in nearly theoretical bulk density at a relatively lower temperature, which is attributed to the superior powder properties. The sintered microstructure, as studied by scanning electron microscopy, revealed the presence of fine grains.

Medium-k dielectric Y2O3 films were directly grown on (100) Si substrates by the pulsed laser deposition (PLD) technique. X-ray photoelectron spectroscopy, variable angle spectroscopic ellipsometry, current-voltage, capacitance-voltage, and high-resolution transmission electron microscopy were used to investigate the composition, thickness, and electrical properties of the grown structures. It has been found that at the interface between the Si substrate and the grown dielectric layer, a SiOx interfacial layer, whose thickness depended on the oxygen pressure used during the PLD growth, was always formed. The main oxygen source for this interfacial layer formation is the physisorbed oxygen trapped inside the grown layer during the laser ablation-deposition process. When trying to reduce the thickness of this low-k interfacial layer by decreasing the oxygen pressure during laser ablation, a marked degradation of the electrical properties of the structures was noticed.