Papers by Keyword: MOD

Abstract: In the present study we prepared NiFe₂O₄, Ni_0.95Cu_0.05Fe₂O₄ and Ni_0.94Cu_0.05Co_0.01 Fe₂O₄ thin films by metallo-organic decomposition method (MOD) using spin coating technique. The samples were characterized by XRD. XRD patterns of thin films confirmed the formation of cubic spinel structure without any secondary phase. For microstructural analysis we characterized samples by Scanning Probe Microscope (SPM). From Atomic force microscopy (AFM), we analyzed surface morphology, calculated grain size, roughness and porosity. It has been found that grain size and roughness affected by Cu, Co substitution. After this we carried out magnetic force microscopy (MFM) on the samples. Effect of substitution on magnetic grains was observed from MFM.

Abstract: Co_0.6Zn_0.4Fe₂O₄ (CZFO), Pb_0.76Ca_0.24TiO₃ (PCT) thin films and Co_0.6Zn_0.4Fe₂O₄ – Pb_0.76Ca_0.24TiO₃(CZFO/PCT) composite thin film were prepared by chemical solution method using metello – organic precursor. Structural and microstructural properties were studied by using XRD and Atomic force microscopy (AFM) respectively. XRD patterns confirme cubic spinel structure for CZFO ferrite and perovskite structure for PCT ferroelectric phase without any impurity phase formation. Grain size and roughness were calculated from AFM images. Grain size and roughness of composite thin film are decreased in comparison to individual phases (CZFO,PCT). Magnetic properties were studied using VSM.

Abstract: Pb (Mg_1/3Nb_2/3)O₃ (PMN) thin films were prepared by metal organic decomposition (MOD) method. The effects of Pb content and annealing temperature on the crystallinity of PMN epitaxial thin films were investigated. The 10at% Pb-excess PMN film annealed at 973 K with facing the film surface against another STO substrate have improved its crystallinity compared with those under another conditions.

Abstract: Pure PVA and composite thin films of poly vinyl alcohol (PVA)/Titanium dioxide (TiO2) were prepared on pre-cleaned glass substrates by Dip Coating Technique (DCT) and Metal Organic Deposition Technique (MODT). EDS and FTIR spectrum were used to identify the composition of the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA. The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The bands observed around 847 cm-1 and 601cm-1 belong to the asymmetric stretching of Ti–O–Ti groups. The last band at 460 cm-1 is due to the bending mode of Ti–O–Ti. The bands covered by Ti-O were located at 540, 700 and 950 cm-1. From the FTIR spectra, it is observed that some of the peaks of composite films were shifted and some of them were disappeared with respect to the pure compounds. This results manifested the conclusion about the specific interactions in composite polymer matrices and hence the complexation. Thus, complex formation in the composite polymer matrices has been confirmed from this analysis. The thickness of the coated films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD-20), gravimetric method and cross checked by optical spectrophotometer. XRD spectra indicated the amorphous nature of the films. Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. Both as grown and annealed films showed predominantly amorphous nature. The observed surface morphology and thermal stability indicated that these films could be used as dielectric layer in organic thin film transistors.

Abstract: Because of the problem that how to formulate standard working hours quickly and accurately in the process of making time quota for enterprises at the present stage, we propose a concept which is a set of operating action and process feature. Considering the similarity of the attribute of process feature between the parts, and seeming the class of locomotive wheels as the object of research, we design a typical template of formulating standard process auxiliary processing time using MOD, this template faces process feature. In actual application, enterprises only have to modify the template slightly in view of the actual situation to meet the requirements.

Abstract: The La1-xAxMnO3 (A=Sr, Ca, Ba) film was prepared by excimaer laser-assisted metal organic deposition (ELAMOD). To understand the important controlling factor of the epitaxial growth using ELAMOD, the effects of the substrate temperature, substrate type, wavelength, and film thickness on the epitaxial growth were investigated. When the film thickness was 200nm with heating at 250°C, a polycrystalline LSMO film was formed on the LAO substrate. On the other hand, at 80nm, an epitaxial LSMO film was formed on the LAO substrate at 500°C. The epitaxial growth of the LSMO film was found to be dependent on the substrate materials and the laser wavelength. The formation of the epitaxial and polycrystalline LSMO films was discussed

Abstract: CeO2 has been considered as one of the most lattice compatible and chemically stable materials for YBa2Cu3O7-x coated conductors. In this paper, we presented the epitaxial growth of CeO2 thin film on both YSZ single crystal and cube textured Ni5W substrates by MOD method. Homogenous, crack-free and dense CeO2 thin films on both substrates with sharp biaxially cube texture were fabricated by post-annealing the precursor films at 1000-1150°C. For the CeO2 film on the textured Ni5W substrate, the FWHM values of (111) Phi-scan and (002) rocking curve were around 6°and 7°, respectively, the surface roughness was less than 2 nm over an area of 1μm×1μm observed by AFM. It was found that the CeO2 thin film improved both the in-plane orientation and surface roughness of the Ni5W substrate, indicating that the as deposited CeO2 films were suitable for the further growth of YBCO superconductor layer.

Abstract: We investigated the effects of hydrogen annealing process on ferroelectricity in SrBi₂Ta₂O₉(SBT) capacitors. The hydrogen-induced degradation of SBT capacitors was found after a hydrogen annealing process. The degraded properties could be recovered by re-crystallization annealing process in O₂ ambient for 30 min. In order to prevent the catalyst reaction of Pt electrode known as an origin of hydrogen-induced degradation, Au top electrode was used. It was confirmed that Au electrode effectively prevented capacitors from degrading during hydrogen process.

Abstract: Ferroelectric characteristics of the 400 nm-thick Sr_xBi_2.4Ta₂O₉(0.7≤x≤1.3) thin films processed by metalorganic decomposition were investigated, and electrical properties of the Pt/Sr_0.85Bi_2.4Ta₂O₉/TiO₂/Si structure prepared using TiO₂ buffer layer were characterized. The Sr-deficient Sr_xBi_2.4Ta₂O₉ films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films. The Sr0.85Bi2.4Ta2O9 film exhibited optimum ferroelectric properties, such as high remanent polarization and low leakage current density, among Sr_xBi_2.4Ta₂O₉ films. A memory window of the Pt/SrxBi2.4Ta2O9/TiO2/Si structure was dependent upon the coercive field of the Sr_xBi_2.4Ta₂O₉ film, and the Pt/Sr_xBi_2.4Ta₂O₉/TiO₂/Si exhibited a maximum memory window of 1.3 V at the sweeping voltage of ±5 V.