Glancing Angle X-ray Diffraction Research Articles

Optical investigation on zinc doped cadmium sulphide nanocrystalline thin films

Optical investigation on blue shift behavior of zinc doped cadmium sulphide nano-crystalline thin films have been prepared by spray pyrolysis method at 375 ± 10 °C. The crystallinity and phase have been characterized by glancing angle X-ray diffraction. The XRD peaks confirm the hexagonal structure of cadmium sulphide. The crystallites sizes are found its range of 15–20 nm. The surface morphology is analyzed by using field emission scanning electron microscopy. The morphology of the film is seen as uniform distribution of homogeneous fine solid grains which are compact in nature. Optical absorption spectrum reveals an absorption peak at 475 nm. Indicating that blue shift due to quantum confinement effect, as a result the direct energy gap is increased and found its value is 2.91 eV. Raman spectrum reveals the longitudinal optical phonon peaks are at 302 cm−1 and 603 cm−1. The noticeable asymmetry and frequency shift confirm the decrease in particle size. X-ray photoelectron spectroscopy reveals the surface composition and binding energy of elements and it confirm the presence of zinc. The photoluminescence spectrum reveals an emission peak at 728 nm is analyzed. Zn doped cadmium sulphide thin film is useful for window material in solar cells and luminescent red phosphor.

Atomic layer deposition of indium oxide thin film from a liquid indium complex containing 1-dimethylamino-2-methyl-2-propoxy ligands

In2O3 thin films were grown from a newly developed, liquid, homoleptic, In-based complex, tris(1-dimethylamino-2-methyl-2-propoxy)indium [In(dmamp)3], and O3 by atomic layer deposition (ALD) at growth temperatures of 150–200°C. In(dmamp)3 exhibited single-step evaporation with negligible residue and excellent thermal stability between 30 and 250°C. The self-limiting surface reaction of In2O3 during ALD was demonstrated by varying the In(dmamp)3 and O3 pulse lengths, with a growth rate of 0.027nm/cycle achieved at 200°C. The In2O3 films grown at temperatures over 175°C exhibited negligible concentrations of impurities, whereas that grown below 175°C had concentrations of residual C of 6–8 at.%. Glancing angle X-ray diffraction revealed that the In2O3 films were polycrystalline in nature when the deposition temperature was greater than 200°C. The In2O3 films grown at 150–200°C exhibited carrier concentrations of 1.5×1018–6.6×1019cm−3, resistivities of 15.1–2×10−3Ωcm, and Hall mobilities of 0.8–42cm2/(Vs).

Bias influence on titanium interlayer for titanium nitride films

This work investigates the deposition of TiN thin films by cathodic arc evaporation on stainless steel AISI 304 substrate for decorative applications. The applied voltage bias on the substrate during the Ti interlayer deposition was varied, and several properties were determined. The chemical profile, crystalline structure and microstructural properties were analysed by glow discharge optical emission spectroscopy, glancing angle X-ray diffraction and SEM techniques respectively. In addition, nanoindentation and sliding tests were performed in order to evaluate the hardness and scratch resistance of TiN thin films. The results showed that the applied voltage bias during the Ti interlayer deposition step could modify some properties of the TiN thin films. Indeed, lower oxygen contents and higher critical loads to start a plastic deformation (scratch resistance) of the TiN thin films are achieved at higher applied voltage biases during the Ti interlayer deposition. A higher scratch resistance is capable of imparting a long term durability of metallic pieces for decorative applications.

Vanadium, V – a new native element mineral from the Colima volcano, State of Colima, Mexico, and implications for fumarole gas composition

AbstractVanadium, V, is a new mineral found in sublimates of high-temperature fumaroles of the Colima volcano, Mexico. The mineral precipitates over a narrow temperature range of 550–680°C, and occurs in association with colimaite (K3VS4) and shcherbinaite (V2O5). Native vanadium was been found on the inner wall of an inserted silica tube and subsequently in the adjacent rock of the Z3 fumarole. Vanadium forms smooth, irregular to flattened crystals, 5–20 μm in diameter. Smaller irregular crystals have also been observed in silica tubes. Due to its small crystal size, its physical properties (hardness, cleavage and density) could not be determined. An EDS spectrum indicated the presence of V, Fe, Al and Ti with an empirical formula calculated on the basis of EPMA analyses of V0.86Fe0.09Al0.04Ti0.01. Gandolfi and glancing-angle X-ray diffraction data showed that the microcrystals were body-centred cubic, space group Im3̄m, a = 3.022(3) Å, V = 27.60 (5) Å3, Z = 2. The five strongest calculated diffraction lines are [ d spacings in Å, (I) (hkl)]: 2.1411 (100)(110), 1.5126 (12)(200), 1.2301 (19)(211), 0.9565 (8)(310) and 8.8090 (11)(321). The calculated density is 6.033 g cm–3. Thermochemical modelling was used to explain why very oxidized gas at Colima precipitates V-bearing minerals and some native elements (vanadium and gold). Vanadium, is the second newly recognized mineral species (after colimaite) collected from an active fumarole in this volcanic crater. The mineral and its name have been approved by the CNMNC (IMA 2012-021a).

Effect of iron doping on the structural and optical properties of CeO2 films

Undoped and Fe-doped CeO2 thin films were fabricated by spin coating on F-doped tin oxide glass substrates followed by annealing at 500 °C for 15 h. The concentration of the dopant was varied from 2 to 10 % iron by weight (metal basic). Glancing angle X-ray diffraction and laser Raman microspectroscopy indicated that the films consisted only of CeO2 without any impurity phases of FexOy. The thickness of the films was determined by dual-beam focused ion beam milling to be ~150 nm for undoped film, while Fe-doped CeO2 films have thickness of ~200 nm for all dopant samples. The transmission spectra from UV–visible spectrophotometry showed a redshift of the absorption edge of the doped films, and the optical indirect band gap of the films decreased from 3.48 to 3.20 eV with increasing dopant concentration. Furthermore, the results have been proposed in the diagram of electron–hole trapping.

Improvement of the thermal stability of nickel silicide using a ruthenium interlayer deposited via remote plasma atomic layer deposition

In this study, the effects of a thin Ru interlayer on the thermal and morphological stability of NiSi have been investigated. Ru and Ni thin films were deposited sequentially to form a Ni/Ru/Si bilayered structure, without breaking the vacuum, by remote plasma atomic layer deposition (RPALD) on a p-type Si wafer. After annealing at various temperatures, the thermal stabilities of the Ni/Ru/Si and Ni/Si structures were investigated by various analysis techniques. The results showed that the sheet resistance of the Ni/Ru/Si sample was consistently lower compared to the Ni/Si sample over the entire temperature range. Although both samples exhibited the formation of NiSi2 phases at an annealing temperature of 800 °C, as seen with glancing angle x-ray diffraction, the peaks of the Ni/Ru/Si sample were observed to have much weaker intensities than those obtained for the Ni/Si sample. Moreover, the NiSi film with a Ru interlayer exhibited a better interface and improved surface morphologies compared to the NiSi film without a Ru interlayer. These results show that the phase transformation of NiSi to NiSi2 was retarded and that the smooth NiSi/Si interface was retained due to the activation energy increment for NiSi2 nucleation that is caused by adding a Ru interlayer. Hence, it can be said that the Ru interlayer deposited by RPALD can be used to control the phase transformation and physical properties of nickel silicide phases.

Optimization and Characterization of Anatase Formed on Anodized Titanium in Phosphoric Acid

Titanium (Ti) is widely used in dental and orthopedic implants because of its good biocombatibility and high corrosion resistance. Titanium oxide (TiO2) has shown to exhibit strong physicochemical bonding between Ti implant and living bone because of its ability to induce bone-like apatite in a body environment. Ti is always coated by an oxide surface layer of 1.5-10 nm thickness. TiO2 crystalline structures; anatase and rutile present several distinctive features, such as photocatalytic behaviour, superhydrophilicity and biocompatible properties. Anodic oxidation is used to modify the surface of pure titanium in a phosphuric acid electrolyte in order to maximize and characterize the TiO2 anatase crystalline phase. In the present work, thick films of the anatase polymorph of TiO2 were formed on commercially pure Ti foil under potentials 200 V-350 V at current densities 40 and 60 mA/cm2 for 10 min. Multiple characterization techniques were used. Glancing angle X-ray diffraction (GAXRD) is used to obtain crystalline phases, field emission scanning electron microscope (FESEM) is used to obtain surface images and water contact angle (WCA) is used to obtain the wettability of the oxide surface. According to GAXRD results the intensity of the major peak increased with increasing applied voltage and current density while decrease with molar concentration. This means that the amount and/or crystallinity of anatase are/is influenced with these parameters. The coated oxides obtained small amount of anatase is comparing to films anodized in H2SO4 electrolyte. Which confirm that slower crystallization in H3PO4 than in H2SO4. FESEM images obtained that as the voltage increased, the film breaks down locally and results in a porous surface. The porosity and the pore size increase with the increasing voltage. The pore size diameter at 300V for 0.3 M can reach up to 1μm. As for WCA results the coated samples at higher voltages (250 V, 300 V and 350 V) and molar concentration 0.3 M have shown more hydrophilic surface, with sample anodized at 350 V at 0.3 M have the lowest contact angle, thus the highest surface energy. While samples anodized at 200 V voltage observed more hydrophobic surface with sample anodized at 200 V at 0.1 M have the lower wettability, thus the lowest surface energy.

Effect of post sputter annealing treatment on nano-structured cadmium zinc oxide thin films

Thin films of cadmium zinc oxide (CdZnO) were deposited on glass substrates by reactive dc magnetron sputtering and post sputter annealed at different temperatures: 350 °C, 400 °C, 450 °C, 500 °C and 550 °C. These films were characterized by glancing angle x-ray diffraction, field emission scanning electron microscopy, photoluminescence, UV–vis–NIR spectroscopy and Hall measurements. The structural results revealed that all these films exhibit hexagonal wurtzite structure with complete c-axis orientation in (002) plane. The transmittance of these films increased with the post sputter annealing treatment and minimum band gap observed for the film that was annealed at 500 °C. The carrier concentration and Hall mobility increased with post sputter annealing, while electrical resistivity decreased with the narrowing optical band gap and increase in the crystallite sizes.

Effect of Ti Sputtering Current on Structure of TiCrN Thin Films Prepared by Reactive DC Magnetron Co-Sputtering

Titanium chromium nitride (TiCrN) thin films were deposited by reactive DC magnetron co-sputtering. The effect of Ti sputtering current (ITi) on the structure of the TiCrN thin films were investigated. The crystal structure, microstructure, thickness, roughness and elemental composition were characterized by glancing angle X-ray diffraction (GAXRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Cr)N solid solution. The as-deposited films exhibited a nanostructure with a crystallite size of less than 40 nm. The crystal size decreased from 39.9 nm to 33.5 nm, while the lattice constants increased from 4.139 Å to 4.162 Å, with increasing of the Ti sputtering current. The film thickness and roughness were found to increase from 397 nm to 615 nm and 3.7 nm to 6.3 nm, respectively, with increasing of the Ti sputtering current. The composition of the as-deposited films varied with the Ti sputtering current. Cross section analysis by FE-SEM showed compact columnar and dense morphology as a result of increasing the Ti sputtering current.

Effect of substrate temperature on structural and optical properties of reactive dc magnetron sputtered CdZnO thin films

Thin films of ternary cadmium zinc oxide (CdZnO) were prepared on glass substrates by dc magnetron sputtering technique at different substrate temperatures (RT, 100°C, 200°C & 300°C). The structural and optical properties of the films are investigated by glancing angle x-ray diffraction (GAXRD) and UV-vis-NIR spectroscopy measurements respectively. GAXRD pattern confirmed the hexagonal wurtzite structure with a preferred grain orientation in (002) direction for all the samples. The optical studies reveal that, the optical band gap was decreased from 3.25eV to 2.88eV with increase of substrate temperature.

Paucity of Nanolayering in Resin-Dentin Interfaces of MDP-based Adhesives

Self-assembled nanolayering structures have been reported in resin-dentin interfaces created by adhesives that contain 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). These structures have been hypothesized to contribute to bond durability. The objective of the present study was to determine the extent of nanolayering in resin-dentin interfaces after application of commercialized 10-MDP-containing self-etch and universal adhesives to human dentin. Seven commercialized adhesives were examined: Adhese Universal (Ivoclar-Vivadent), All-Bond Universal (Bisco, Inc.), Clearfil SE Bond 2, Clearfil S3 Bond Plus, Clearfil Universal Bond (all from Kuraray Noritake Dental Inc.), G-Premio Bond (GC Corp.), and Scotchbond Universal (3M ESPE). Each adhesive was applied in the self-etch mode on midcoronal dentin according to the respective manufacturer’s instructions. Bonded specimens (n = 6) were covered with flowable resin composite, processed for transmission electron microscopy, and examined at 30 random sites without staining. Thin-film glancing angle X-ray diffraction (XRD) was used to detect the characteristic peaks exhibited by nanolayering (n = 4). The control consisted of 15%wt, 10%wt, and 5%wt 10-MDP (DM Healthcare Products, Inc.) dissolved in a mixed solvent (ethanol and water weight ratio 9:8, with photoinitiators). Experimental primers were applied to dentin for 20 s, covered with hydrophobic resin layer, and examined in the same manner. Profuse nanolayering with highly ordered periodicity (~3.7 nm wide) was observed adjacent to partially dissolved apatite crystallites in dentin treated with the 15% 10-MDP primer. Three peaks in the 2θ range of 2.40° (3.68 nm), 4.78° (1.85 nm), and 7.18° (1.23 nm) were identified from thin-film XRD. Reduction in the extent of nanolayering was observed in the 10% and 5% 10-MDP experimental primer-dentin interface along with lower intensity XRD peaks. Nanolayering and characteristic XRD peaks were rarely observed in specimens prepared from the commercialized adhesives. The sparsity of nanolayering in resin-dentin interfaces created by commercialized adhesives challenges its clinical effectiveness as a mechanism for improving bond longevity in dentin bonding.

Metal-boride phase formation on tungsten carbide (WC-Co) during microwave plasma chemical vapor deposition

Strengthening of cemented tungsten carbide by boriding is used to improve the wear resistance and lifetime of carbide tools; however, many conventional boriding techniques render the bulk carbide too brittle for extreme conditions, such as hard rock drilling. This research explored the variation in metal-boride phase formation during the microwave plasma enhanced chemical vapor deposition process at surface temperatures from 700 to 1100°C. We showed several well-adhered metal-boride surface layers consisting of WCoB, CoB and/or W2CoB2 with average hardness from 23 to 27GPa and average elastic modulus of 600–730GPa. The metal-boride interlayer was shown to be an effective diffusion barrier against elemental cobalt; migration of elemental cobalt to the surface of the interlayer was significantly reduced. A combination of glancing angle X-ray diffraction, electron dispersive spectroscopy, nanoindentation and scratch testing was used to evaluate the surface composition and material properties. An evaluation of the material properties shows that plasma enhanced chemical vapor deposited borides formed at substrate temperatures of 800°C, 850°C, 900°C and 1000°C strengthen the material by increasing the hardness and elastic modulus of cemented tungsten carbide. Additionally, these boride surface layers may offer potential for adhesion of ultra-hard carbon coatings.

Structural, optical and electrical properties of heavy ion irradiated CdZnO thin films

The thin films of CdZnO were deposited on glass substrates using dc magnetron sputtering technique and investigated after heavy ion-irradiations of 100MeV Au ions with the fluences ranging from 1×1011ions/cm2 to 1×1013ions/cm2. The structural, optical and electrical properties of the irradiated and pristine films were studied by glancing angle X-ray diffraction (GAXRD), UV–vis–NIR spectroscopy and Hall effect measurement. The structural characterization using GAXRD pattern shows an enhancement of crystallinity up to the ion fluence of 5×1012ions/cm2, and the crystallinity decreases at the highest fluence of 1×1013ions/cm2 and these films exhibit hexagonal wurtzite crystal structure (002) with a c-axis orientation. The optical transmittance spectra reveals a red shift and the optical band gap decreases upon ion-irradiation with the minimum band gap at the ion fluence of 5×1012ions/cm2. The average transmittance of the thin film of CdZnO increases from 75% to 85% after irradiation (up to 5×1012ions/cm2). The atomic force microscopy image of the films reveals that roughness decreases up to the fluence of 5×1012ions/cm2 and increases at higher fluences. The films irradiated with a fluence of 5×1012ions/cm2 would show better electrical properties like low resistivity, high carrier concentration and mobility compared to other irradiated films.

Chemistry of surface nanostructures in lead precursor-rich PbZr0.52Ti0.48O3 sol–gel films

We present a study of the chemistry of the nanostructured phase at the surface of lead zirconium titanate PbZr0.52Ti0.48O3 (PZT) films synthesized by sol–gel method. In sol–gel synthesis, excess lead precursor is used to maintain the target stoichiometry. Surface nanostructures appear at 10% excess whereas 30% excess inhibits their formation. Using the surface-sensitive, quantitative X-ray photoelectron spectroscopy and glancing angle X-ray diffraction we have shown that the chemical composition of the nanostructures is ZrO1.82−1.89 rather than pyrochlore often described in the literature. The presence of a possibly discontinuous layer of wide band gap ZrO1.82−1.89 could be of importance in determining the electrical properties of PZT-based metal-insulator-metal heterostructures.

Formation and characterization of Ni/Al Ohmic contact on n+-type GeSn

In this study, a Ni/Al Ohmic contact on a highly doped n-type GeSn has been investigated. A specific contact resistivity as low as (2.26±0.11)×10−4Ωcm2 was obtained with the GeSn sample annealed at a temperature of 450°C for 30s. The linear Ohmic behavior was attributed to the low resistance of the Ni(GeSn) phase; this behavior was determined using glancing-angle X-ray diffraction, and the quantum tunneling current through the Schottky barrier narrowed because of high doping; this phenomenon was confirmed from the contact resistance characteristics at different temperatures from 45 to 205K.

Optimization and Characterization of Anatase Formed on Anodized Titanium in Sulfuric Acid

Titanium (Ti) is widely used in dental and orthopedic implants because of its good biocombatibility and high corrosion resistance. Titanium oxide (TiO2) has shown to exhibit strong physicochemical bonding between Ti implant and living bone because of its ability to induce bone-like apatite in a body environment. Ti is always coated by an oxide surface layer of 1.5-10 nm thickness. TiO2 crystalline structures; anatase and rutile present several distinctive features, such as photocatalytic behaviour, superhydrophilicity and biocompatible properties. Anodic oxidation is used to modify the surface of pure titanium in a sulphuric acid electrolyte in order to maximize and characterize the TiO2 anatase crystalline phase. In the present work, thick films of the anatase polymorph of TiO2 were formed on commercially pure Ti foil under potentials 100V-140V at current densities 40 and 60 mA/cm2 for 10 min. Multiple characterisation techniques were used and found that the maximum level of significantly formed anatase intensity where no significant rutile formation is observed at potential 140 V according to Glancing angle X-ray diffraction (GAXRD). Field Emission Scanning Electron Microscope (FESEM) images have shown porous surfaces as the applied voltage increased. Water contact angle (WCA) values observed hydrophilicity on the coated surfaces with samples anodized at 120 V have the highest wettability.

Phase analysis and thermal stability of thin films synthesized via solid state reaction of Ni with Si1 − xGex substrate

The products of the solid state reaction involving ultra-thin Ni film (6nm) and Si1−xGex layers (Ge 25 and 55at.%), were analysed using sheet resistance (Rs), glancing angle X-ray diffraction (GIXRD), scanning electron and atomic force microscopy (SEM, AFM) techniques. The reaction was carried out via rapid thermal process (RTP) annealing using two different steps (RTP1 and RTP2) while applying a selective etch (SE) in between them. The intermediate and the end reaction products resulting after RTP1 and RTP2 were found to be dependent on the Ge content, forming Ni-rich silicide (Ni2Si) and NiSi on Si75Ge25, while Ni-rich germanide (Ni5Ge3) and NiGe were obtained by using Si45Ge55. Though the onset of intermediate Ni-rich silicide or germanide phase formation occurs at similar RTP1 temperature (275°C), the reaction completion to yield low resistive phase NiSi or NiGe phase results at different RTP2 temperatures (400°C vs 350°C). Based on the volume expansion, a resistivity value of 25μΩcm was obtained for the synthesized NiGe (12nm) and NiSi (14nm) layers. Independent of the phases obtained, the films were found to be closed and homogeneous and exhibit rms roughness of 0.5–0.8nm as evidenced by SEM and AFM analysis. Thermal stability studies carried out on NiSi and NiGe thin films, post RTP1/RTP2, show the latter phase to have limited stability and result in Rs degradation starting already at 475°C due to phase decomposition.

Effect of Sm3+ on the structural, optical, magnetic and electrical properties of electrochemical deposition of ZnSe thin films

Zn1−xSmxSe thin films with an Sm3+ concentration of x = 1 to 5 mole % were grown on ITO substrates at 50 °C using the electrochemical deposition (ECD) technique. The structural, optical, magnetic and electrical properties were analyzed as a function of the Sm3+ ion concentration. The glancing angle x-ray diffraction (GAXRD) characterisation of doped systems at various Sm3+ mole fractions x confirmed the exclusive formation of the host ZnSe with the zinc blende structure. The optical transmission spectra show that the percentages of transmission and band gap energy are different for pure and Sm3+ doped ZnSe thin films. Photoluminescence (PL) spectra of 1 to 5 mole % Sm3+ ion doped ZnSe thin films show two distinct ZnSe and Sm3+ related emissions, both of which are excited via the ZnSe host lattice. A sharp luminescence peak from Sm3+ doped ZnSe at 1.83 eV, which can be assigned as the 4G5/2 → 6H9/2 transition of Sm3+, was observed. The magnetization of Sm3+ doped ZnSe thin films was measured as a function of the magnetic field and temperature. The magnetic behaviour of magnetic semiconductor Sm3+ doped ZnSe, with no secondary phase, is reported. Electrical measurement showed that when the Sm3+ ion is incorporated, the electrical resistivity drops and the carrier concentration increases.

Study of thickness dependent sputtering in gold thin films by swift heavy ion irradiation

Gold thin films of varying thickness (10–100nm) grown on silica substrates by e-beam evaporation method were irradiated by 120MeV Au ions at 3×1012 and 1×1013ionscm−2 fluences. Irradiation induced modifications of these films were probed by glancing angle X-ray diffraction (GAXRD), atomic force microscopy (AFM), Rutherford backscattering spectrometry (RBS) and surface enhanced Raman scattering (SERS). Irradiation didn’t affect the structure, the lattice parameter or the crystallite size, but modified the texturing of grains from [111] to [220]. RBS indicated thickness dependent sputtering on irradiation. The sputtering yield was found to decrease with increasing thickness. AFM indicated increase of roughness with increasing irradiation fluence for films of all thickness. In agreement with the AFM observation, the gold nanostructures on the surface of 20nm thick film were found to increase the SERS signal of acridine orange dye attached to these structures. The SERS peaks were amplified by many fold with increasing ion fluence. The effect of 120MeV Au ion irradiation on the grain texture, surface morphology and SERS activity in addition to the thickness dependent sputtering in gold thin films are explained by the thermal spike model of ion-matter interaction.

Glancing angle XRD analysis of particle stability under self-ion irradiation in oxide dispersion strengthened alloys

We have used glancing-incident angle X-ray diffraction (GIXRD) to study the stability of oxide nanoclusters in an Fe–14Cr–0.2Ti–0.3Y2O3 ODS alloy. High dose self-ion irradiation produces damaged layers a few hundred nanometres deep normally requiring time-consuming, site-specific techniques to study them. We have shown that GIXRD provides an effective way to study the damage depth profile by varying the incident angle, and that the Y2Ti2O7 nanoclusters in these alloys are disrupted by high dose irradiation at temperatures from 150 to 973K.