Synthesis and characterization of Zn1-xMnxS nanocrystalline films prepared on glass substrates

Nanocrystalline Zn1-xMnxS films (x=0.04, 0.08 and 0.12) were deposited on glass substrates at 400 K using a simple resistive thermal evaporation technique. All the deposited films were characterized by chemical, structural, morphological, optical and magnetic properties. Scanning electron microscopy and atomic force microscopy studies showed that all the films investigated were in nanocrystalline form with the grain size lying in the range 10–20 nm. All the films exhibited cubic structure and the lattice parameters increase linearly with composition. The absorption edge shifted from the higher-wavelength region to lower wavelengths with increase in Mn concentration. The magnetization increased sharply with increase of the Mn content up to x=0.08 and then decreased with further increase of the Mn content. Particularly, Zn0.92Mn0.08S concentration samples show a weak ferromagnetic nature, which might be the optimum concentration for optoelectronic and spintronic device applications

Structural and morphological properties of thermally evaporated Zn1−xMnxSZn_{1-x}Mn_xS nanocrystalline films

In recent years the dilute magnetic semiconductors have received much attention due to the complementary properties of semiconductor and ferromagnetic behaviour. Nanostructured $Zn_{1-x}Mn_xS$ films $(0 \leq x \leq 0.25)$ were deposited on glass substrates at room temperature (300 K) using simple resistive thermal evaporation technique. All the deposited films were characterized by chemical, structural and morphological studies. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) studies showed that all the films investigated were in nanocrystalline form with the grain size lying in the range 8 – 22 nm. All the films exhibited cubic structure and the lattice parameter varied linearly with composition

Microstructure and nanohardness of the diluted magnetic semiconducting Cd1−XMnXSCd_{1-X}Mn_XS nano-crystalline films

$Cd_{1-X}Mn_XS$ nano-crystalline films $(0 \leq X \leq 0.5)$ were formed on glass substrates by thermal evaporation technique at room temperature (300 K). AFM studies showed that all the films were in nano-crystalline form with the grain size varying in the range between 36 and 58 nm and exhibited hexagonal structure of the host material. The lattice parameters varied linearly with composition, following Vegard’s law in the entire composition range. The nanohardness and Young’s modulus decreased sharply with 'Mn' content upto x=0.3 and increased with high Mn content

Structural and photoluminescence properties of Zn1-xMnxO nanoparticles for optoelectronic device applications

High intense photoluminescence Zn1-xMnxO powder samples were prepared by simple solid state reaction method. All the samples were studied for their morphological, structural and photoluminescence properties. X-ray diffraction (XRD) results showed that all the samples were polycrystalline with wurtzite structure. The lattice parameters ‘a’ and ‘c’ varied linearly with composition following Vegard’s law in this composition range. Scanning Electron Microscopy (SEM) studies showed that all the samples investigated were in nanoparticles form with the particle size lying in the range 25 – 50 nm. The room temperature photoluminescence spectra show that the UV emission gradually shifted towards the higher energy side. A blue-shift in the position along with an intense blue emission band was observed with the Mn concentrations, which are ascribed to the quantum confinement effect

Structural and Electrical Properties of Resistive Thermal Evaporated Cd1−xMnxSCd_{1-x}Mn_xS Nano-Crystalline Films

Thin films of $Cd_{1-x}Mn_xS$ $(0\leq x \leq 0.5)$ were prepared on window glass substrates by resistive vacuum thermal evaporation. All the films were deposited at 300 K and the films annealed at 373 K, 473 K and 573 K for 1 hour in a vacuum of $10^{-6} m$. bar. The as-deposited and the annealed films were characterized by EDAX, XRD, AFM, electrical conductivity and Hall Effect studies

Synthesis and dc magnetic susceptibility of the diluted magnetic semiconducting Cd1−xMnxSCd_{1-x}Mn_xS nanocrystalline films

Nanocrystalline films of $Cd_{1-x}Mn_xS(0\leq x \leq0.5)$ with grain size of 36–58 nm were deposited on glass substrates at a substrate temperature of 300K using resistive thermal evaporation. All the films exhibited wurtzite structure and the lattice parameters varied linearly with composition.The magnetic susceptibility increased sharply with Mn content 'x' and decreased with increase of the temperature

Structural and optical investigations of TiO2 films deposited on transparent substrates by sol-gel technique

An inexpensive and effective simple method for the preparation of nano-crystalline titanium oxide (anatase) thin films at room temperature on different transparent substrates is presented. This method is based on the use of peroxo-titanium complex, i.e. titanium isopropoxide as a single initiating organic precursor. Post-annealing treatment is necessary to convert the deposited amorphous film into titanium oxide (TiO2) crystalline (anatase) phase. These films have been characterized for X-ray diffraction (XRD) studies, atomic force microscopic (AFM) studies and optical measurements. The optical constants such as refractive index and extinction coefficient have been estimated by using envelope technique. Also, the energy gap values have been estimated using Tauc's formula for on glass and quartz substrates are found to be 3.35 eV and 3.39 eV, respectively. (C) 2008 Elsevier B.V. All rights reserved

Strain, luminescence, and electrical properties of Zn1−xMnxSZn_{1-x}Mn_xS nanocrystalline films prepared on silicon wafers

Nanocrystalline $Zn_{1−x}Mn_xS$ films (0 \leq x \leq 0.25) were deposited on silicon wafers at 473 K using a simple resistive thermal evaporation technique. Morphological and structural measurements revealed that all the films investigated were nanocrystalline with a cubic structure. The lattice parameter increased linearly with Mn concentration. The surface roughness of all the films was shown to be in the range 1.2–3.5 nm. A blueshift in the photoluminescence was observed in the films with increasing Mn concentration along with an intense ultraviolet emission and orange-yellow emission, which are ascribed to the quantum confinement effect. The composition had a significant influence on the orange-yellow emission intensity as well as peak positions. The excitation wavelength of all the samples was 330 nm and emission wavelengths were observed around 410–560 nm. The presence of many recombination sites, surface areas, and defect types leads to broad band photoluminescence emission lines instead of sharp bands. The electrical resistivity as well as activation energy decreased with increasing Mn concentration

Structural and optical investigations of TiO2 films deposited on transparent substrates by sol-gel technique

An inexpensive and effective simple method for the preparation of nano-crystalline titanium oxide (anatase) thin films at room temperature on different transparent substrates is presented. This method is based on the use of peroxo-titanium complex, i.e. titanium isopropoxide as a single initiating organic precursor. Post-annealing treatment is necessary to convert the deposited amorphous film into titanium oxide (TiO2) crystalline (anatase) phase. These films have been characterized for X-ray diffraction (XRD) studies, atomic force microscopic (AFM) studies and optical measurements. The optical constants such as refractive index and extinction coefficient have been estimated by using envelope technique. Also, the energy gap values have been estimated using Tauc's formula for on glass and quartz substrates are found to be 3.35 eV and 3.39 eV, respectively

Structural and photoluminescence properties of thermally evaporated Cd1−xMnxSCd_{1-x}Mn_xS nano-crystalline films

Thin films of $Cd_{1-x}Mn_xS (0\leq x \leq 0.5)$ were formed on glass substrates by resistive vacuum thermal evaporation. All the films were deposited at 300 K and the films were annealed at 373, 473 and 573 K for 1 h in a vacuum of $10^{-6}$ mbar. Atomic force microscopy (AFM) studies showed that all the films investigated were in nano-crystalline form with a grain size in the range 36–82 nm. All the films exhibited a wurtzite structure of the host material. The lattice parameters varied linearly with composition following Vegard’s law in the entire composition range. Photoluminescence studies showed that two distinct emission bands were observed for each $Cd_{1-x}Mn_xS$ compound. One corresponds to internal transition and the other one is due to the transition of $Mn^{2+}$ ions in interstitial sites or in small ‘Mn’ chalcogenic clusters