A single phase Y-type hexagonal ferrite Sr2Co1.7Mg0.3Fe11.2Sn0.4Zn0.4O22 was synthesized by sol–gel auto combustion method. The microstructured and magnetic properties of this Y-type hexagonal ferrite composition have been investigated. Different experimental techniques such as differential thermal and thermo-gravimetric analyses, X-ray diffraction, Fourier transform infrared spectroscopy, high resolution field emission scanning electron microscopy and vibrating sample magnetometry were used to investigate the sample. The X-ray diffraction (XRD) patterns confirm single phase Y-type hexagonal ferrite powders were obtained after calcinations at 1000oC and showed that the crystallite size is 44 nm.The microstructures of the pure powders appeared as a hexagonal platelet-like structure and particles size was 90-210 nm.The saturation magnetization (Ms) and the coercivity (Hc) of the samples were in the range, 28.34–48.47 emu/g and 637-1108 Oe, respectively. The heat treatment temperature increased the magnetization, following a decrease in coercivity due to intermediate phases replacement by single Y-type hexaferrite, Which can be used as soft magnetic materials in multilayer inductors for high frequency applications.

In the present study, Cr2O3 nanostructured and conventional (microstructured) coatings have been prepared by atmospheric plasma spraying (APS) on carbon steel substrates. Phase composition and structural properties of coatings were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Also, the mechanical properties of coatings such as microhardness were evaluated. Nanostructured Cr2O3 coating exhibited a bimodal microstructure consisting of nanosized particles retained from the powder and microcolumnar grains formed through the resolidification of the molten part of powder, whereas the microstructure of conventional Cr2O3 coating consisted of columnar-grain splats. The results revealed that nanostructured coating, due to unique microstructure container of nanozones, presented improved microhardness and fracture toughness as compared to the conventional coating.

Cr2O3 feedstock of nano and micron size particles were coated on low carbon steel by APS process. Ni-Al bond coat was used to improve the adhesion of coatings to substrate. Microstructural investigations were conducted by FESEM and X-ray diffractometery (XRD) was utilized for structural analysis. Wear behavior of the coatings was studied by ball on disk testing using alumina balls at room temperature and 300 and 500oC under a load of 30N. Experimental results showed that both coatings consist of a layered structured of melted and semi-melted splats. However the nanostructured coating contained more semi-melted splats resulting more porosity compared to the microstructured coating. Tribological evaluation of the coatings revealed that the nanostructured coating exhibits lower friction coefficient in comparison to the microstructured Cr2O3 coating. Wear rate of the coatings decreased by increasing the temperature so that at 300 and 500oC. The nanostructured coating presented better wear resistance. Improvement of wear resistance and decreasing the friction coefficient in nanostructured coating at different temperatures can be attributed to the effect of nanoparticles, higher hardness and also formation of compacted and adhesive tribofilm on the surface of the coating.

Our recent advances in solid-state optoelectronic materials and devices will be reviewed. In the area of glass optics, fabrication of novel microstructured and multi-core fibers and their use in realizing single mode lasers will be summarized. In organic and plastic optics, photo refractive polymers for 3D display applications and nonlinear optical polymers for high speed modulators in RF photonic and remote antenna applications will be discussed. Our progress in medical optics including adaptive eyewear and imaging will also be described.

Intrinsically conducting polymers (ICPs) such as polyaniline and polypyrrole which have advantages such as high conductivity, high flexibility, ease synthesis routes, high stability and good mechanical properties, have aroused intense of many researches for various application such as electrolytic capacitors, electronic and electro chromic devices, sensors, light-weight batteries, membrane separation and radar absorbing materials (RAMs). In this research, polypyrrole (PPy) with novel morphology was synthesized successfully, using a microstructured MnO2 microcube as a self-reactive template and oxidizing agent for the beginning of the polymerization reaction. MnCO3 microcubes were synthesized by hydrothermal method at 150°C. They were utilized as precursors for MnO2 microcube synthesis. XRD patterns of MnO2 and PPy revealed that the MnO2 templates consumed almost completely as an initiator or an oxidizing agent in polymerization reaction. Also, FESEM images demonstrated that PPy structures are totally inherited their morphologies from MnO2 templates.

In this research work, an attempt has been made to examine the different welding parameters which affect the weldability of 304H Austenitic stainless steel (ASS) welded joint using the proper filler wire. Chemical composition of filler wire was same as that of base metal. Further this study addressed the combined effect of various welding parameters on the metallurgical and mechanical properties of the weldments. Welding was carried out at different parameters such as welding wire speed, shielding gas flow rate, welding current and arc voltage etc. Tensile tests and V-notch Charpy tests were conducted as per ASTM to determine the mechanical properties of the welded specimens. In order to determine the microstructured changes that occurred, the interface regions of the welded specimens were examined by microscope. As a result, it is reported that changing the shielding gas flow rate and wire feed speed affects the microstructure and mechanical properties of weldment. Impact tests reveal that toughness of the welded joint increases with increasing in welding current, while ultimate tensile strength (UTS) first increases and then decreases.