Characterization of pure and copper-doped iron tartrate crystals grown in silica gel

Single crystal growth of pure and copper-doped iron tartrate crystals bearing composition Cu _x Fe_(1???x)C₄H₄O₆·nH₂O, where x = 0, 0.07, 0.06, 0.05, 0.04, 0.03, is achieved using gel technique. The elemental analysis has been done using energy-dispersive X-ray analysis (EDAX) spectrum. The characterization studies such as Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), magnetic analysis and thermal analysis have been done for crystals with x = 0 for pure iron tartrate and with x = 0.05 for copper-mixed iron tartrate crystals. A detailed comparison has been made between pure and doped crystals.     

Synthesis and characterization of gel-grown cobalt tartrate crystals

Crystals of cobalt tartrate are grown from the gel using chemical reaction method. The functional groups are found from Fourier transform infra red spectroscopy (FTIR). The OH stretching mode owing to water, carbonyl group, CH stretching modes and metal–oxygen stretching are identified. The unit cell dimensions, interaxial angles and unit cell volume are found from powder X-ray diffraction studies (XRD) which show the orthorhombic nature of the crystal. The magnetic study is used to find the magnetic susceptibility and magnetic moment of the grown crystal. It reveals the magnetic nature of the crystal. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are done to find the thermal properties of the crystal which manifest the water of hydration in the crystal. The variation of dielectric constant with respect to the applied frequency shows the polarization property of the crystal. The AC conductivity is increased proportionally with increase in frequency. The reverse nature is found for the AC resistivity. The nature of the composition of the crystals affects the dielectric properties.     

Effect of barium doping on the physical properties of zinc oxide nanoparticles elaborated via sonochemical synthesis method

The aim of this work is to study the effect of barium (Ba) doping on the optical, morphological and structural properties of ZnO nanoparticles. Undoped and Ba-doped ZnO have been successfully synthesized via sonochemical method using zinc nitrate, hexamethylenetetramine (HMT) and barium chloride as starting materials. The structural characterization by XRD and FTIR shows that ZnO nanoparticles are polycrystalline with a standard hexagonal ZnO wurtzite crystal structure. Decrease in lattice parameters from diffraction data shows the presence of Ba²⁺ in the ZnO crystal lattice. The morphology of the ZnO nanoparticles has been determined by scanning electron microscopy (SEM). Incorporation of Ba was confirmed from the elemental analysis using EDX. Optical analysis depicted that all samples exhibit an average optical transparency over 80%, in the visible range. Room-temperature photoluminescence (PL) spectra detected a strong ultraviolet emission at 330 nm and two weak emission bands were observed near 417 and 560 nm. Raman spectroscopy analysis of Ba-doped samples reveals the successful doping of Ba ions in the host ZnO.