Narrow Results

Silver bromide (AgBr) nanowires were grown in the pores of ion track membrane. Simple chemical reaction technique was used where pores in the membrane act as reactors. Uniform morphology of nanowires was found using scanning electron microscopy (SEM). An X-ray diffraction (XRD) study shows the crystalline structure. Energy dispersive X-ray fluorescence (EDXRF) technique was used to study the composition of AgBr nanowires. Optical band gap of AgBr nanowires determined using absorption spectra was found to be higher than the bulk.

ZnO nanorods assembled in flower shaped morphology have been successfully synthesized using low power microwave irradiation in a very short duration. The diameter and length of the rods were within 150–190 nm (tip diameter ~15 nm) and 2 μm, respectively, with an aspect ratio of 20–22. The synthesized nanorods were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared microscopy (FT-IR), photoluminescence (PL) and magnetization measurements. The XRD and FT-IR results indicate that ZnO nanorods have the pure wurtzite structure with lattice parameters a and c of 3.254 and 5.197 Å, respectively. The selected area electron diffraction (SAED) pattern reveals that the ZnO nanorods are single crystal in nature and grow along [001] plane. Room-temperature PL spectrum of the as-grown ZnO nanorods shows a near-band-edge (NBE) emission peak and defect induced emissions. Magnetization measurements indicate that ZnO nanorods exhibit room temperature ferromagnetism with remanent magnetization (Mr) and coercivity (H_c) about 2.92 × 10^-4 (emu/g) and 29.75 Oe, respectively, which may be due to the presence of defects in the ZnO nanorods.

Polyaniline (PANI) is recognized as one of the most important conducting polymers due to its high conductivity and good stability. In this paper, polyaniline/silver (PANI/Ag) nanocomposites were synthesized by in-situ polymerization of aniline using ammonium peroxydisulphate (APS) as oxidizing agent with varying concentration of Ag nanoparticles colloids (0 ml, 25 ml and 50 ml). Silver nanoparticles were synthesized separately in colloidal form from silver nitrate (Ag₂NO₃) with the help of reducing agent sodium borohydride (NaBH₄). The PANI/Ag nanocomposites were characterized by XRD, SEM, AFM, UV-visible, temperature dependent resistivity and dielectric measurements. All samples show a single phase nature of the nanoparticles. The electrical resistivity as function of temperature was measured in the temperature range 298–383 K, which indicates a semiconducting to metallic transition at 373 K and 368 K for 25 ml and 50 ml silver colloid samples, respectively.

XRD pattern of $\beta$-Ga₂O₃ powder, synthesized through template-free two step hydrothermal method at low temperature thoroughly, is investigated by imposing different methods of analysis. Both crystallite sizes and micro-strains of the micro-structures are analyzed and compared. Along with the traditional Scherrer’s formula (S-average, LF and LFTZ), modified Williamson–Hall (W-H) method with UDM, USDM and UDEDM and Size-Strain Plot (SSP) method were used for the investigation. Stress and defect energy densities were calculated from USDM and UDEDM modified W-H plots of the powder sample, respectively. Detailed analysis of the crystallite size and micro-strain from different methods/models was done. Obtained crystallite sizes and micro-strains from different models were compared with the results obtained from TEM analysis. It was found that crystallite sizes obtained from UDM modified W-H analysis and SSP models well coincided with crystallite size observed from TEM micrograph.