Suresh Sagadevan

Hydrothermal synthesis of zirconium oxide nanoparticles and its characterization

The paper presents the preparation and investigations of zirconium oxide (ZrO2) nanoparticles that were synthesized by hydrothermal method. The products were characterized by means of powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-absorption spectroscopy and photoluminescence (PL) spectroscopy. The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The spherical shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR and Raman spectrum ascertained the strong presence of ZrO2 nanoparticles. The optical properties were obtained from UV–visible absorption spectrum and also PL emission spectrum. The dielectric constant and the dielectric loss were measured as a function of frequency and temperature.

Investigations on the Synthesis, Optical and Electrical Properties of TiO2 Thin Films by Chemical Bath Deposition (CBD) method

Titanium dioxide (TiO2) thin films were prepared by Chemical Bath Deposition (CBD) method. The X-ray diffraction (XRD) analysis was used to examine the structure and to determine the crystallite size of TiO2 thin film. The surface morphology of the film was studied using Scanning Electron Microscopy (SEM).The optical properties were studied using the UV-Visible and photoluminescence (PL) spectrum. Optical constants such as band gap, refractive index, extinction coefficient and electric susceptibility were determined. The FT-IR spectrum revealed the strong presence of TiO2. The dielectric properties of TiO2 thin films were studied for different frequencies and different temperatures. The AC electrical conductivity test revealed that the conduction depended both on the frequency and the temperature. Photoconductivity study was carried out in order to ascertain the positive photoconductivity of the TiO2 thin films.

Investigation of the Structural, Optical and Electrical Properties of Copper Selenide Thin Films

Copper selenide (CuSe) thin films were prepared by chemical bath deposition (CBD) method. X-ray diffraction (XRD) analysis was used to study the structure and crystallite size of CuSe thin film. The grain size and the surface morphology were studied using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The optical properties were studied using the UV-Visible transmission spectrum. The dielectric properties of the synthesized CuSe thin films were studied at different frequencies and different temperatures. Further, electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the CuSe thin films were determined. The AC electrical conductivity study revealed that the conduction depended both on the frequency and the temperature. The temperature dependent conductivity study confirmed the semiconducting nature of the films. Photoconductivity measurements were carried out in order to ascertain the positive photoconductivity of the CuSe Thin films. This paper covers what all has been stated above besides discussing the results of I-V characteristics.

Structural, Optical, Morphological and Dielectric Properties of Cerium Oxide Nanoparticles

Cerium oxide (CeO2) nanoparticles were prepared by the precipitation method. The average crystallite size of cerium oxide nanoparticles was calculated from the X-ray diffraction (XRD) pattern and found to be 11 nm. The FT-IR spectrum clearly indicated the strong presence of cerium oxide nanoparticles. Raman spectrum confirmed the cubic nature of the cerium oxide nanoparticles. The Scanning Electron Microscopy (SEM) analysis showed that the nanoparticles agglomerated forming spherical-shaped particles. The Transmission Electron Microscopic (TEM) analysis confirmed the prepared cerium oxide nanoparticles with the particle size being found to be 16 nm. The optical absorption spectrum showed a blue shift by the cerium oxide nanoparticles due to the quantum confinement effect. The dielectric properties of cerium oxide nanoparticles were studied for different frequencies at different temperatures. The dielectric constant and the dielectric loss of the cerium oxide nanoparticles decreased with increase in frequency. The AC electrical conductivity study revealed that the conduction depended on both the frequency and the temperature.

Optical and electrical smart response of chemically stabilized graphene oxide

Graphene oxide (GO) was prepared using a modified Hammer’s technique and by utilizing a sonochemical approach. The paper deals with the synthesis and the characterization of GO besides the structural, morphological, optical and electrical properties of GO. Phase formation of the prepared sample was examined with powder X-ray diffraction (XRD), the typical surface morphology was carried out by utilizing Scanning electron microscopy (SEM) and the high resolution Transmission Electron Microscopy (HR-TEM). The different functional groups were recognized by utilizing FT-IR and Raman spectroscopy. The optical properties were studied utilizing optical absorption and photoluminescence (PL) spectra. At various frequencies and temperatures the dielectric properties of the GO, such as the dielectric constant, the dielectric loss, and AC conductivity were studied. Further, the electrical behaviour of GO was analysed using I-V and C-V characteristics. These novel findings shed focus on high yield electronic material GO, which can only be realized as the field moves forward and makes more significant advances in smart opto-electronic devices.

Synthesis and characterization of TiO2/graphene oxide nanocomposite

TiO2–graphene oxide (TiO2/GO)-nanocomposite was synthesized by the thermal hydrolysis method. The solution processibility of graphene oxide offers a practical route to carbon-based composites, samples were portrayed by X-ray diffraction, UV–visible absorption spectroscopy, scanning electron microscopy, transmission electron microscopy, and fourier transformed infrared spectroscopy. Phase formation of the TiO2/GO composite was inspected with powder X-ray diffraction (XRD), the typical surface morphology was done by using scanning electron microscopy (SEM) and the high-resolution transmission electron microscopy (HR-TEM). The different functional groups were perceived by using FT-IR and raman spectroscopy. The optical properties were contemplated using optical ingestion and photoluminescence (PL) spectra. The conductivity and dielectric properties were examined in the different frequencies and the different temperatures. The outcomes demonstrated that the dielectric consistent and the dielectric loss were frequency and temperature dependent. The AC conductivity at various temperatures demonstrated thermal conduction. Furthermore, the electrical conductivity of TiO2/GO composite was investigated utilizing current density (J)- volteage (V) measurements. In this presentation, we clarify the underlying mechanisms of TiO2/GO-nanocomposite alignment and itself has significant potentiality as an optical and electrical response.

Structural, dielectric and optical investigation of chemically synthesized Ag-doped ZnO nanoparticles composites

The sol–gel technique was used in the chemical synthesis and characterizations based on structural, morphological, optical and electrical studies of pure and Ag-doped zinc oxide (ZnO) nanoparticles. X-ray diffraction, scanning electron microscopy, energy Dispersive X-ray spectrometry, transmission electron microscope, ultraviolet spectroscopy, photoluminescence and FT-IR analysis were used to perform the characterization of the morphological analysis, optical studies, phase purity and crystalline size. The Powder X-ray diffraction results proved polycrystalline nature of ZnO with a hexagonal wurtzite structure. Debye-Scherrer’s formula was used to evaluate the average crystallite size of pure and Ag-doped ZnO. Their values have been determined to be 14 and 18 nm respectively. To examine the various functional groups FTIR was utilized. The unique aggregation of the particles was stated by the scanning electron microscopy investigation and transmission electron microscope analysis was used to substantiate the nanosphere formation. Here, the estimated optical band gap value for pure and Ag-doped ZnO nanoparticles was 3.22 and 3.17 eV, respectively. UV–visible spectroscopy was used to perform this process. Photoluminescence studies have proved the Ag-doped ZnO sample of the blue shift emission bands. At different frequencies and temperatures, under specific conditions, the dielectric properties like dielectric constant, dielectric loss and AC conductivity of Ag-doped ZnO nanoparticles were analyzed.Graphical Abstract

Synthesis of tungsten carbide nanoparticles by hydrothermal method and its Characterization

Tungsten carbide (WC) nanoparticles were synthesized by hydrothermal method and their structural characterization was performed by using powder X-ray diffraction , Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). SEM and TEM study revealed their morphology and the particle size of WC nanoparticle respectively. Dielectric properties of WC nanoparticles were determined by using LCR meter at different frequencies and different temperatures. Dielectric constant, dielectric loss, and electrical a.c. conductivity were measured. Electronic properties such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy, and electronic polarizability of the WC nanoparticles were also estimated.

Synthesis and characterization of CoWO4 nanoparticles via chemical precipitation technique

This paper has for its content the synthesis and the findings of structural, surface morphological, optical and electrical studies of CoWO4 nanoparticles. Precipitation method was employed for the synthesis of CoWO4 nanoparticles. To determine the average grain size of CoWO4 nanoparticles the X-ray diffraction pattern was used. The presence of CoWO4 nanoparticles was confirmed by the FT-IR spectrum. The scanning electron microscopy analysis revealed the facts about the surface morphology of CoWO4 nanoparticles. The transmission electron microscopic analysis helped to measure the size of the particle formed. The absorption spectrum and photoluminescence spectrum made it possible to analyze the optical properties of CoWO4 nanoparticles. The contribution of this work is that the dielectric properties such as the dielectric constant, the dielectric loss, and the AC conductivity of the CoWO4 nanoparticles were studied at different frequencies and temperatures.

Scalable synthesis of CdS–Graphene nanocomposite spectroscopic characterizations

Cadmium sulfide–Graphene nanocomposite was synthesized by the chemical precipitation method. Phase formation of the CdS–Graphene nanocomposite was inspected with powder X-ray diffraction, the typical surface morphology was done by using field emission scanning electron microscopy and the transmission electron microscopy, equipped with energy dispersion spectroscopy. The different functional groups were identified by using FT-IR and Raman spectroscopy. The optical properties were analyzed using UV absorption spectrum and photoluminescence spectra. The dielectric properties were examined in the different frequencies and the different temperatures.