There is a substantial amount of literature dealing with many aspects of synthesis and characterization of pure and doped binary compounds including Mn-doped ZnO which has been widely studied due to its superb properties as a dilute magnetic semiconductor (DMS). Aspects concerning doping limits for these compounds is an important stage in the search for new materials. Samples of Zn1-xMnxO nanocrystal were synthesized at temperatures of 180 °C and 200 °C using wet or liquid phase synthesis method. Dopant concentrations x=0.5, 1, 1.5, 2, 2.5, 5, 10, 20, 30, 40 and 50 per cent were studied. Powder x-ray diffraction (PXRD) patterns of the samples were analyzed with a view to determining the onset of secondary phases and hence the solubility limit of the dopant. The solubility limit for Mn in ZnO samples synthesized at temperature of 200 °C is realized at x <20%. For samples synthesized at temperature of 180 °C, the solubility limit is x <0.5%.

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Single phase iron pyrite (FeS 2) films have been successfully deposited on ITO-coated glass substrates using a 3-electrode electrochemical system with graphite as the counter electrode and Ag/AgCl as the reference electrode. In this single-step electrodeposition, the FeS precursor thin film was directly electrodeposited on the conductive substrate from the electrolytic bath solution which contained FeSO 4 •7H 2 O as an iron source, and Na 2 S 2 O 3 •5H 2 O as a sulfur source. The deposition was carried out potentiostatically at a constant potential of −0.9 V vs. Ag/AgCl at room temperature. The growth of the iron pyrite phase was achieved by annealing the as-deposited at 500˚C for an hour in an ambient of sulfur to form the pyrite phase. For sulfurization, two different techniques, one using the Kipp's apparatus and a second, which involved heating elemental sulfur at 200˚C, were used for the production of the sulfur gas. X-ray diffraction analyses of the sulfurized films showed that both sulfurization techniques appeared to form the pyrite phase, however, the second method yielded films with maximum crystalline order and stoichiometry with no discernable impurity peaks. Optical absorption measurements revealed the existence of a direct transition with an estimated band gap of 1.75 eV. SEM micrograph showed a compact morphology with a rough surface made up of crystallites of irregular shapes and sizes with well-defined edges, covering the entire substrate. EDAX analysis of the film was consistent with the formation of FeS 2 pyrite thin films.

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