Spin Coated YSZ Thin Films on Silicon Substrate
Yttria Stabilized Zirconia (YSZ) thin films (<10 μm) were fabricated by spin coating technique on silicon (Si). Parameters such as concentration ratio of YSZ powder to solvent were varied accordingly. The effects of these variations were investigated and discussed. Using X-ray Diffraction and Raman Spectroscopy, the crystal structure of the samples were determined. The 8-YSZ thin films have cubic fluorite structure. The X- ray diffraction patterns were in agreement with the samples' Raman spectra. Pores were evident on single coated substrates but were minimized using higher YSZ concentration. Index Terms—Yttria Stabilized Zirconia,YSZ, spin-coating, thin film ——————————  ——————————
Nanocrystalline zirconia-yttria system - a Raman study
Abstract Nano sized zirconia (ZrO 2 ) powders doped with different amount of yttria (Y 2 O 3 ) (3, 5 and 8 mol%) were prepared through coprecipitation method. The crystallite size estimated from the X-ray peak broadening is around 10 nm. Phase identification was carried out using XRD and Raman spectroscopy. Raman spectroscopic study of the synthesized materials show clear evidence of the presence of single phase cubic structure in the case of 8 mol% Y 2 O 3 doped fully stabilized zirconia (8Y-FSZ); tetragonal phase in the case of zirconia doped with 3 mol% Y 2 O 3 (3Y-TZP-tetragonal zirconia polycrystal) and a mixture of cubic and tetragonal phases for 5 mol% Y 2 O 3 doped partially stabilized zirconia (5Y-PSZ). Raman technique is therefore an effective tool to distinguish the phases present in the calcined nano sized powders of zirconia.
Similarities in protozoan and flatworm habituation behavior.
ONE problem in the study of habituation in protozoa is that similar results, given the same experimental manipulations, may not be obtained in metazoa. I shall compare habituation behaviour in the protozoan Spirostomum with that in the micrometazoan Rhabdocoel flatworm Stenostomum; it remains to be shown whether there is a correspondence between protozoa and metazoa both in behaviour and in their underlying chemical processes. Both these organisms contract in response to mechanical and touch stimuli: when subjected to repeated stimulation, they habituate1. Furthermore, the more intense the stimulus, the longer it takes for habituation to occur1.