Glancing Angle X-ray Diffractometer Research Articles

A study of 8 MeV e-beam on localized defect states in ZnO nanostructures and its role on photoluminescence and third harmonic generation

In this article we have explored an effect of electron beam irradiation (EBI) on physical and nonlinear optical properties ZnO thin nano films. Nanostructured ZnO thin films were grown by low cost spray pyrolysis technique. The irradiation dosage has been fixed at 5 kGy, 10kGY, 15 kGy and 20 kGy. The structural investigation by Glancing angle X-Ray Diffractometer (GAXRD) confirms a polycrystalline phase of ZnO with wurtzite structure. The variation in the surface morphology upon EBI has been demonstrated using 2D and 3D Atomic force microscopy (AFM) images. Nanoscope software analysis quantifies the variation in surface roughness and average particle height upon EBI. The defect states created in the films upon irradiation experiments were investigated using UV–visible spectrophotometer, Room temperature Photoluminescence (RTPL), Raman and X-ray photoelectron spectroscopy (XPS). The increase in urbach tail validates the creation of localized defect states in the films The Gaussian fitting on RTPL spectra shows the quenching in the luminescent centers upon irradiation arised as result of recombination of vacancy defects. Phonon confinement model fitting on Raman spectra endorses that shift in the phonon modes observed on irradiation is due to spatial confinement of phonons. The elemental composition and impurity states of the EBI ZnO thin films were studied using XPS spectra. The shift in the binding energy of Zn and O elements infers the electron beam induced changes in the films. The electron beam irradiation has resulted in the increment of third order optical susceptibility χ(3) 3.5 × 10−4 esu to 8.13 × 10−3 esu due to the enhancement of electronic transition to different defect levels formed in the films and through local heating effects arising due to continuous wave (CW) laser illumination. The enhanced THG signal investigated using Nd:YAG laser at 1064 nm and 8 ns pulse width shows the promising features of EBI ZnO films for frequency tripling applications.

Precipitation of Hydroxyapatite on Pure Titanium Substrate via Single Step Anodic Oxidation

Anodic oxidation is an electrochemical method that deposits ceramic coatings on the metal substrates to improve the bioactivity of implant. In this study, a novel approach was proposed to precipitate hydroxyapatite (HAP) directly on the surface of pure titanium through anodic oxidation approach. As part of the proposed approach, a new formulation of electrolyte was introduced, which consists of 0.04 M β-glycerophosphate (β-GP), 0.4 M calcium acetate (CA) and 1.0 M sulphuric acid (H2SO4). The approach herein only requires a single step to precipitate the HAP directly on the surface of titanium through anodisation process within the electrolyte. High purity titanium foils were anodised in 0.04 M β-GP + 0.4 M CA + 1.0 M H2SO4 at 350 V and 70 mA.cm-2 for 10 minutes at varying fractions of mixture volumes of H2SO4 (0-100 vol%). The surface properties of anodised titanium were characterised by using several methods, namely the field emission scanning electron microscopy (FESEM), glancing angle X-ray diffractometer (GAXRD) and goniometer. The outcome of the characterisation showed that the needle-like HAP was precipitated on the titanium, whereby anodising in electrolyte contains 12.5 vol% H2SO4. Combinations of anatase, rutile, titanium, tricalcium phosphate (Ca3O8P2) and calcium diphosphate (Ca2O7P2) elements were detected within the anodised titanium, whereby the anodising in electrolyte contains 50 vol% H2SO4.

Effect of Ultrasonic Amplitude on Surface Properties of Anodised Titanium for Biomedical Application

Anodic oxidation is an electrochemical method for the production of ceramic films on a metallic substrate. It is a simple and low cost method to produce bioactive material. This work describes the effect of ultrasonic amplitude on the surface properties of anodised titanium. Specifically, high purity titanium foils were anodised in mixture of 0.04 M β-glycerophosphate disodium salt pentahydrate (β-GP) and 0.4 M calcium acetate monohydrate (CA) at 350 V and 70 mA.cm-2 for 10 minutes. The ultrasonic amplitude was varied from 20-60 μm. Next, field emission scanning electron microscopy (FESEM) glancing angle X-ray diffractometer (GAXRD) and atomic force microscopy (AFM) were used to characterise the anodised titanium. The results showed that application of sonication is able to remove the entrapped bubbles on the anode surface and enhance the oxidation process. The pores size and surface roughness were increased as increasing of ultrasonic amplitude. At ultrasonic amplitude ≥ 50 μm, rutile TiO2 was formed on the surface of oxide layer. It was found that the sonication is a simple method to improve the surface properties of anodised titanium for implant applications.

Preparation of Bioactive Titanium Film via Anodic Oxidation in Agitation Condition

Anodic oxidation is a well-established surface modification method which combines electric field driven metal and oxygen ion diffusion to produce protective oxide layer on metals. This method has been widely used to modify the surface properties of titanium and its alloy. This present study aims to investigate the effect of agitation speed on the surface properties of anodised titanium. At first, the high purity titanium foils were anodised in mixture of 0.04 M β-glycerophosphate disodium salt pentahydrate (β-GP) and 0.4 M calcium acetate monohydrate (CA) at 350 V and 30 mA.cm-2 for 10 minutes at different agitations speed (300 rpm - 1500 rpm). Next, surface properties of anodised titanium were characterised by digital single-lens reflex camera (DSLR camera), field emission scanning electron microscopy (FESEM) and glancing angle X-ray diffractometer (GAXRD). At lower agitation speed (≤ 900 rpm), surface of anodised titanium covered by small donut-shaped pores. With increasing of agitation speed (≥ 1100 rpm), the oxide layer became more porous and covered by larger donut-shaped pores. Rutile TiO2 peaks were detected at agitation speed more than 1100 rpm. Agitation condition is believed to be an effective method to enhance the surface properties of anodised titanium for biomedical applications.

Effect of Bath Temperature on Surface Properties of Anodised Titanium for Biomedical Application

Anodic oxidation is an electrochemical method to deposit ceramic coatings on the metals substrate to improve the bioactivity. This study aims to investigate the effect of bath temperature on the surface properties of anodised titanium. High-purity titanium foil was modified by anodising in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA). The experiments were carried out at 350 V, 30 mA.cm-2 for 10 minutes at different bath temperature (4-100 °C). Field emission scanning electron microscopy (FESEM), glancing angle X-ray diffractometer (GAXRD) and goniometer were used to characterise the surface morphology, mineralogy and wettability of anodised titanium, respectively. The results showed that porosity and crystallinity of surface decreased as increasing of bath temperature. Interestedly, the α-tricalcium phosphate (α-TCP) was deposited on the samples which anodisation at higher bath temperature (≥ 60 °C) and resulted high hydrophilicity behaviour even the surface was found relatively smooth.

Electrochemical Atomic Layer Deposition and Characterization of CdTe and PbTe Thin Films

This study reports the cycle chemistries involved in depositing CdTe and PbTe nanofilms. An automated thin-layer flow cell electrodeposition system was used to deposit the films at room temperature. Cyclic voltammetry was used to study the Underpotential Deposition (UPD) of the compounds. The monolayer/cycle deposition rate was also monitored in order to insure that the film is depositing at a uniform rate. The chemical composition of the films was characterized using Energy-Dispersive X-ray Spectroscopy (EDS) on a Scanning Electron Microscope (SEM). The crystallinity of the films was studied using a glancing angle X-ray diffractometer. The bandgaps of the films were calculated using measured optical reflection data.

Influence of N₂ Partial Pressure on Structure and Mechanical Properties of TiAlN/Al₂O₃ Multilayers.

TiAlN/Al2O3 multilayers with different Ar/N2 ratios were deposited on Sisubstrates in different N2 partial pressure by magnetron sputtering. The crystalline and multilayer structures of the multilayers were determined by a glancing angle X-ray diffractometer (XRD). A nanoindenter was used to evaluate the hardness, the elastic modulus and scratch scan of the multilayers. The chemical bonding was investigated by a X-ray Photoelectron Spectroscopy (XPS). The maximum hardness (36.3 GPa) and elastic modulus (466 GPa) of the multilayers was obtained when Ar/N2 ratio was 18:1. The TiAlN/Al2O3 multilayers were crystallized with orientation in the (111) and (311) crystallographic planes. The multilayers displayed stably plastic recovery in different Ar/N2 ratios. The scratch scan and post scan surface profiles of TiAlN/Al2O3 multilayers showed the highest critical fracture load (Lc) of 53 mN for the multilayer of Ar/N2 = 18:1. It indicated that the multilayer had better practical adhesion strength and fracture resistance.

Liquid polycarbosilane derived SiC coating on silicon (1 1 1) wafer for enhanced mechanical properties

Silicon carbide coating on silicon (111) wafer was deposited by modified chemical vapor deposition (CVD) method using liquid polycarbosilane (LPCS) as precursor at three different moderately high temperatures in presence of Argon gas. Glancing angle X-ray diffractometer and Fourier Transform Infrared Spectroscopy reveals smooth β-SiC coating and its subsequent transformation into α-SiC on silicon substrate. In all the temperature the film was found to be uniform with a thickness ranging from 0.6–1.2μm. The average particle size as can be seen from FESEM ranges from 7 to 385nm approximately, the lowest range being (7–20nm) which hitherto has not yet been reported using LPCS as precursor for SiC. Moreover the coated samples show substantial increment of hardness (∼18.8GPa) and toughness (∼1.51MPam1/2), both of which increases with increase in deposition temperature. The smooth and thin SiC coating on silicon formed in three different moderate temperatures compared to very high temperature for other CVD assisted coating along with enhanced hardness and toughness makes this a promising material in critically harsh environment required for microelectromechanical systems (MEMS) application.

Fabrication of Ag:TiO2Nanocomposite Thin Films by Sol-Gel Followed by Electron Beam Physical Vapour Deposition Technique

Ag:TiO2nanocomposite films have been synthesized by sol-gel method followed by electron beam physical vapour deposition. Targets for this deposition were prepared by a hydraulic press using a powder containing Ag and TiO2prepared by sol-gel technique. Microstructure, surface, and plasmonic properties of nanocomposite films were studied using glancing angle X-ray diffractometer, atomic force microscopy, field emission secondary electron microscopy, and UV-Vis spectroscopy. Microstructural study reveals that Ag nanoparticles are embedded in TiO2matrix consisting of mixed phases of anatase and rutile. Size estimation using Scherrer formula reveals that average crystallite size of Ag nanoparticles is 23 nm. Surface morphological studies indicate that deposited films are uniform and intact to the substrate and have very low value of root mean square roughness. Optical studies exhibit a surface plasmon resonance induced absorption band in visible region, which is the characteristic feature of Ag nanoparticles. The intensity of this absorption band is found to increase with the increase in deposition time. Multiple peaks observed in absorption band were explained using the concepts of extended Mie scattering. Preliminary experiments also suggested that these nanocomposite films exhibit promising photocatalytic properties, which can be used for water treatment.

The effect of Cr/Zr chemical composition ratios on the mechanical properties of CrN/ZrN multilayered coatings deposited by cathodic arc deposition system

CrN/ZrN multilayer coatings with various Cr/Zr chemical compositions ratio were fabricated by a cathode arc deposition system. The Cr/Zr atomic ratios of the CrN/ZrN multilayer coatings were controlled, ranging from 1 to 2.5. The chemical composition of CrN/ZrN multilayer thin films was determined by a field emission electron probe microanalyzer (FE-EPMA). The phase composition of multilayer coatings was analyzed by a glancing angle X-ray diffractometer. Microstructures of the thin films were examined by field emission scanning electron microscopy (FE-SEM). Nanoindentation, the Daimler−Benz Rockwell-C (HRC-DB) adhesion, microhardness, pin-on-disc wear tests and scratch tests were used to evaluate the hardness, adhesion, toughness and tribological properties of the thin films, respectively. It was found that the hardness and tribological properties were strongly influenced by the Cr/Zr chemical composition ratios of the CrN/ZrN multilayer coatings. Optimal mechanical properties and the maximum hardness of 28GPa were achieved for the coating when the Cr/Zr atomic ratio was 2.1.

무전해법으로 Slide Glass 위에 도금된 Ni층의 접착력에 미치는 열처리의 영향

Surface modification before coating nickel by coupling agents and/or etchant of glass did not provide enough adhesive strength of electroless nickel deposits on glass. Effect of heat treatments on hardness as well as adhesion of nickel deposits was studied by using tape test for adhesion, nanoindenter for hardness and glancing angle x-ray diffractometer (GAXRD) for phase characterization. Heat treatment improved hardness as well as adhesion. XRD results give that the improvements of adhesion and hardness are due to the formation of <TEX>$NiSiO_4$</TEX> around the interface between the nickel deposits and the glass and the precipitation of <TEX>$Ni_3P$</TEX> causing precipitation hardening, respectively. The details in effects of heat treatment on adhesion and hardness are described here.

Strong amorphization of high-entropy AlBCrSiTi nitride film

Amorphous coatings, particular nitride systems, are of interest for numerous practical applications. Nevertheless, at present only a few amorphous nitride coating systems have been considered, the most notably being the (TM, Si)N system (transition metal (TM)=Ti, Zr, W, Mo). The present study provides an alternative approach for producing amorphous nitride films with high thermal stability up to 700°C for 2h. Films are deposited from an equimolar AlBCrSiTi target in various argon/nitrogen atmospheres at different substrate temperatures. It is found that above the nitrogen flow ratio (i.e. RN=N2/N2+Ar) of 28.6% a near equal ratio between target elements and nitrogen is approached, thus indicating the coatings have the chemical formula of (AlBCrSiTi)N. The glancing-angle X-ray diffractometer and transmission electron microscope investigations indicate that the coatings, regardless of nitrogen concentration or deposition temperature (up to 500°C), are amorphous. Thermal treatment shows that the amorphous structure of this (AlBCrSiTi)N coating is maintained up to 700°C when annealing for 2h in vacuum. At annealing temperatures of 800°C and above, the amorphous films transform into a simple NaCl-type face-centered cubic solid solution. Even after annealing at 1000°C for 2h, the grain size is only 2nm. High entropy effect, large lattice distortion effect, and sluggish diffusion effect are proposed to account for the formation of amorphous nitrides.

Influence of bilayer period and thickness ratio on the mechanical and tribological properties of CrSiN/TiAlN multilayer coatings

Nanostructured CrSiN/TiAlN multilayer coatings were deposited by a bipolar asymmetric reactive pulsed DC magnetron sputtering system. The thickness ratio of CrSiN to TiAlN layers was fixed at 1:1. The bilayer periods of the coatings were controlled to be from 6 to 40nm. Furthermore, two CrSiN/TiAlN multilayer coatings with the same bilayer period (20nm) but different CrSiN/TiAlN thickness ratios (2:8 and 8:2) were also deposited to explore the influence of thickness ratio on the mechanical properties of the multilayer coatings. The crystalline structures of the coatings were determined by a glancing angle X-ray diffractometer. The microstructures of thin films were examined by a scanning electron microscopy and a transmission electron microscopy, respectively. A nanoindenter, a micro Vickers hardness tester, and a pin-on-disk wear tester were used to evaluate the hardness, the toughness and the tribological properties of the thin films, respectively. The maximum hardness of the multilayers was obtained when the bilayer period was at 10nm for the coating with the same thickness ratio of CrSiN to TiAlN layers (1:1). Meanwhile, the thickness ratio of CrSiN to TiAlN layer had great influence on the hardness and the toughness properties of the multilayer coatings. The hardness and the toughness of the CrSiN/TiAlN multilayer coatings increased as the individual TiAlN layer thickness increased.

Microstructure, mechanical and electrochemical properties evaluation of pulsed DC reactive magnetron sputtered nanostructured Cr–Zr–N and Cr–Zr–Si–N thin films

Cr–Zr–Si–N thin films with various Zr contents were deposited by a bipolar asymmetric pulsed DC reactive magnetron sputtering system. In addition, a Cr–Zr–N film without Si addition was fabricated as a reference. The influence of Zr on the constitution, microstructure, mechanical, tribological and electrochemical properties of Cr–Zr–Si–N films was investigated. The microstructure of thin films was determined by a glancing angle X-ray diffractometer (GA-XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. A nanoindenter, a Vickers micro hardness tester and pin-on-disk wear tests were adopted to evaluate the hardness, toughness and tribological properties of thin films, respectively. The electrochemical properties of thin films were also evaluated in 3.5 wt.% NaCl aqueous solution. In case of the Cr–Zr–Si–N films, the Si content was fixed around 6–8 at.% and various Zr contents ranging from 0.5 to 13.6 at.% were achieved by changing the Zr target power density. In comparison to the Cr–Zr–N reference film, the addition of ~ 7.0 at.% Si in Cr–Zr–Si–N films resulted in a refined columnar structure and enhanced mechanical and anti-corrosion properties. A lattice constant expansion of these films was observed with increasing Zr content. A nanostructured thin film with around 5–10 nm grain size was obtained in case of a Cr–13.6 at.% Zr–6.8 at.% Si–N film. In general, the hardness, plastic deformation resistance and corrosion resistance increased also with increasing Zr content in the Cr–Zr–Si–N films. The Cr–Zr–Si–N film containing 13.6 at.% Zr exhibited a combination of high hardness, good mechanical properties, adequate tribological performance and excellent corrosion resistance in this study.

Role of surface properties of MoO 3-doped SnO 2 thin films on NO 2 gas sensing

The role of surface morphology of MoO 3-doped SnO 2 thin film on the gas sensing properties is analyzed. SnO 2 thin films doped with 1, 3, 5 and 10 wt% MoO 3 are prepared by sol–gel spin coating process. Structural and morphological properties are studied using glancing angle X-ray diffractometer, atomic force microscopy, transmission electron microscopy and high resolution transmission electron microscopy. Energy dispersive X-ray analysis and X-ray photoelectron spectroscopy studies are used for chemical analysis. A good correlation is found between the characteristics of the surface and gas sensing properties of these films. MoO 3 addition is found responsible for increase in acidic nature of films which in turn increases their sensitivity and selectivity towards NO 2 gas.

Characteristics of Cr 2N/Cu multilayered thin films with different bilayer thickness

Nanostructured Cr 2N/Cu multilayer coatings were deposited periodically by a bipolar asymmetric reactive pulsed DC magnetron sputtering system. The crystalline structure of multilayer coatings was determined by a glancing angle X-ray diffractometer. Microstructures of thin films were examined by an atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. A nanoindenter, a micro Vickers hardness tester and pin-on-disk wear tests were used to evaluate the hardness, fracture toughness and tribological properties of the thin films, respectively. Electrochemical tests in 3.5 wt.% NaCl aqueous solution were performed to evaluate the corrosion resistance of multilayered coatings . The bilayer period of the nanostructured multilayer coatings were controlled within the range from 5 to 40 nm. It was found that the hardness increased with decreasing bilayer period and leveled off at small periods around 6–12 nm. The Cr 2N/Cu multilayered coatings with bilayer periods of 5 and 6 nm exhibited a combination of high hardness, good tribological and good anticorrosion performance in this study.

The anodization voltage influence on the properties ofTiO2 nanotubes grown by electrochemical oxidation

A systematic study of titanium dioxide (TiO2) nanotubes (NTs) grown by electrochemical anodization inNH4F + glycerol electrolyte has been carried out in a broad range of anodizationvoltage of 5–350 V and acid concentration of 0.1–0.7 wt%. It is found thatNTs can be grown in the voltage range from 10 to 240 V. The maximumNH4F acid concentration at which NTs can be formed decreases with the anodization voltage(Va). The maximumNH4F acid concentrationis 0.7% for Va<60 V, and itdecreases to 0.1% at Va = 240 V. Glancing angle x-ray diffractometer (GAXRD) measurements show that as-grown amorphousTiO2 transforms to the anatase phase when annealed at400 °C, and further transforms to the rutile phase at annealing temperatures higher than500 °C. The transition temperature from anatase to rutile phase depends on the anodizationconditions. The electrical resistivity of the NT increases by eight orders of magnitude whenVa increases from 10 to 240 V.

Optical and structural properties of nanocrystalline copper oxide thin films prepared by activated reactive evaporation

Nanocrystalline Cu 2O thin films have been synthesized using an activated reactive evaporation technique. Structural and optical characterizations of these films have been carried out using: glancing angle X-ray diffractometer; Fourier transform infrared spectrometer; transmission electron microscope; and UV-VIS-NIR spectrophotometer. The nanocrystallite size in these films was varied by varying deposition parameters. Optical studies show a direct allowed transition and a shift in the optical absorption edge from the bulk value with nanocrystallite size and stoichiometry of these films. These results show that single phase nanocrystalline Cu 2O thin films can be synthesized at a relatively low substrate temperature using the activated reactive evaporation technique. These studies indicate that nanocrystallinity results in the stability of cubic Cu 2O phase in these films.

Formation of highly oriented GeBiSe films from the as-deposited amorphous state by annealing

As-deposited amorphous GeBiSe films were crystallized by thermal and laser annealing. Their structural properties were studied using a glancing angle X-ray diffractometer (GAXRD) and a transmission electron microscope (TEM). Films were crystallized into either a polycrystalline or a highly oriented state, depending on the choice of parameters, such as annealing temperature, rate and duration, and substrate nature and composition. All phases have been identified. The effect of annealing conditions on the relative proportion of these phases has been investigated. A wide range of surface topographical features, such as pyramidal needle shapes of 3 μm length and spherical crystallites with average sizes of 0.35–2 μm, were observed on annealing. The laser scan parameters have been optimized to only obtain crystallization. The film composition and annealing parameters have been optimized in order to obtain strongly oriented crystalline films with a smooth surface topography.

Structural and photocurrent–voltage characteristics of tungsten oxide thin films on p -GaAs

An n-type WO3 thin film on a p-type GaAs substrate has been investigated in terms of its structural, electrical, and photocurrent–voltage characteristics. Crystallization of the monoclinic phases of WO3 occurred at 400 °C as identified by a glancing angle x-ray diffractometer. Above 400 °C, small traces of gallium oxide (Ga2O3)were observed along with higher intensities of the monoclinic peaks. The formation of Ga2O3 was confirmed by a depth profile analysis using an Auger electron spectrometer. Electrical resistivity measured by the van der Pauw method was influenced by the crystalline nature and the interfacial states induced by the diffused atoms from each side of WO3 and GaAs. A high photocurrent density of 7.5 mA/ cm2 at −1.0 V (vs SCE) appeared at the crystalline WO3 on p-type GaAs at 400 °C resulting from effective carrier movement through the interfaces.