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The local interaction within poly(vinylidene fluoride)/poly(3,4‐ethyelenedioxythiophene):poly(styrelenesulfonate) (PVDF/PEDOT:PSS) composite films has been explored in this study. Vibrational and impedance spectroscopy were used extensively to investigate the potential interactions within the moieties of PVDF and PEDOT:PSS in the composite. The increased concentration of PEDOT:PSS used as additives enhanced the dielectric constant of the composite films significantly. Both the AC conductivity and the estimated mobility also increased in the composite films with increasing additives. X‐ray absorption spectroscopy gave an insight into the local chain interactions within the polymer composite films. A shift in the C K‐edge toward higher energy confirmed the local interaction of the polymer moieties, suggesting a change in the polymer chain structure due to the possible association of moieties. [ABSTRACT FROM AUTHOR]

In this work, the preparation of "Ag" alloying Cu2ZnSnSe4 films using a two‐step process, comprising vacuum evaporated ([Sn/ZnSe/Ag/Sn/ZnSe/Cu] × 2) precursor layer deposition on glass substrates followed by low‐temperature pre‐annealing treatment (PAT) in Se ambiance (200–400 °C) for 30 min and high‐temperature annealing at 500 °C for 1 min, is reported. The low‐temperature PAT provides adequate Se diffusion into precursor layers and plays a pivotal influence on the growth and properties of (Cu,Ag)2ZnSnSe4 films. The Zn/Sn and Se/metals ratios are found to be varied in the range 0.77–1.32 and 1.07–0.86 with PAT (200–400 °C) followed by annealing at 500 °C for 1 min. The precursor layers are pre‐annealed at 300 °C for 30 min, followed by annealing at 500 °C for 1 min, found to be nearly stoichiometric with uniform distribution of constituents. The valence states of the constituents are confirmed by X‐Ray photoelectron spectroscopy. Both X‐Ray diffraction and Raman studies confirm the formation of single‐phase (Cu,Ag)2ZnSnSe4 along (112) orientation with a strong Raman mode at 194 cm−1. Large and well‐defined grains with a mean size of 0.7 μm are seen in the field‐emission scanning electron microscope images. The (Cu,Ag)2ZnSnSe4 films exhibit a direct bandgap of 1.12 eV and p‐type conductivity with high mobility, 5.23 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

It is known that Schiff bases and their metal complexes have many properties in different biological systems and this varies with its structural properties. This paper has described the method for synthesis of Schiff base ligand (SB1) and derived Co (II) complex of this ligand. The synthesized metal complex is characterized by X‐ray diffraction (XRD), field emission scanning electron microscope (FE‐SEM), and Fourier‐transform infrared spectroscopy (FTIR). XRD shows the crystalline state of the complex and Schiff base as well as FE‐SEM shows the surface morphology and FTIR is used to characterize functional groups, bonding types, and nature of complex. [ABSTRACT FROM AUTHOR]

Undoped ZnO and Zn1−xGdxO nanoparticles are made using a sono‐chemical co‐precipitation approach. X‐ray diffraction and transmission electron microscopy investigations verified the formation of a wurtzite structure with spherical geometry. All the samples are found to be nanocrystalline by transmission electron microscopy, with crystallite diameters ranging from 14 to 22 nm. The optical constants are calculated via diffuse reflectance spectroscopy. The Urbach energy and photoluminescence spectrum both showed that all doped nanoparticle samples contained defects and disorder due to vacancies. The band structure finding suggest that the forbidden gap of ZnO may change due to the conduction band shift, Burstein‐Moss shift, and shrinkage effect. The near band emission in the ultraviolet region and deep level emission of the photoluminescence spectrum are both strong and decreased with increasing Gd3+ concentration. Studies using X‐ray absorption near edge spectroscopy revealed that the host nano‐lattice Zn sites are substituted with Gd3+ cations to preserve the symmetry with minor distortion. Investigations into charge transfer through the oxygen bands (Gd‐O‐Zn) are made using O K‐edge spectra. The defect emission bands identified through Gd doping indicated that these emissions may be changed for ZnO samples, which could be advantageous for applications in phosphors and light‐emitting devices. [ABSTRACT FROM AUTHOR]

Herein, the effect of microstructure on the electronic, and superconducting properties of niobium mononitride (NbN) thin films grown using a high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (dcMS) is studied. X‐ray reflectivity, cross‐sectional scanning electron microscopy and atomic force microscopy measurements suggest that the film grown with dcMS has a non‐uniform distribution of islands with loosely packed columns while the HiPIMS grown film has a smoother surface and a denser microstructure. Although the X‐ray diffraction measurements show a single‐phase rock‐salt‐type crystal structure in both cases, the local and electronic structure analyzed using N K‐edge X‐ray absorption near edge structure measurements reveals the evidence of a large amount of Nb vacancies in dcMS‐NbN while HiPIMS‐NbN film is closer to stoichiometry. The ordered structure of HiPIMS‐NbN sample results in a relatively higher superconducting transition temperature of 15.2 K and lower normal state resistivity of 90 μΩ cm with a moderate critical field of 18 T and smaller coherence length of 4.2 nm. These results suggest HiPIMS can be utilized to grow high‐quality superconducting thin films of few nanometers required in modern technological devices such as single‐photon detectors, superconducting quantum interference devices. [ABSTRACT FROM AUTHOR]

The valence and conduction band offset in FeNiO/CuNiO bilayer film are studied utilizing X‐ray photoelectron spectroscopy and UV–vis spectroscopy. The bilayer film is grown on Si substrate employing ion beam sputtering technique using a mixture of argon and oxygen gases at 25% oxygen partial pressure. From the precise knowledge of the valence band maxima energies and core‐level energy positions in the single‐layer film and the corresponding shifts in the bilayer film, the valence and conduction band offsets are estimated to be 0.8 and 0.3 eV, respectively. From the computed band offset data, a type‐I band alignment is identified at the interface of the grown bilayer film, which facilitates the knowledge of carrier transport mechanism and is highly attractive for the realization of efficient room‐temperature optoelectronic device. [ABSTRACT FROM AUTHOR]

A prototype in situ X‐ray absorption near‐edge structure (XANES) system was developed to explore its sensitivity for ultra‐thin films of iron‐nitride (Fe‐N), cobalt‐nitride (Co‐N) and nickel‐nitride (Ni‐N). They were grown using DC‐magnetron sputtering in the presence of an N2 plasma atmosphere at the experimental station of the soft XAS beamline BL01 (Indus‐2, RRCAT, India). XANES measurements were performed at the N K‐edge in all three cases. It was found that the N K‐edge spectral shape and intensity are greatly affected by increasing thickness and appear to be highly sensitive, especially in low‐thickness regions. From a certain thickness of ∼1000 Å, however, samples exhibit a bulk‐like behavior. On the basis of the obtained results, different growth stages were identified. Furthermore, the presence of a molecular N2 component in the ultra‐thin regime (<100 Å) was also obtained in all three cases studied in this work. In essence, this prototype in situ system reveals that N K‐edge XANES is a powerful technique for studying ultra‐thin films, and the development of a dedicated in situ system can be effective in probing several phenomena that remain hitherto unexplored in such types of transition metal nitride thin films. [ABSTRACT FROM AUTHOR]

We report huge change in impedance of Fe doped hydroxyapatite Ca9.9Fe0.1(PO4)6(OH)2 in presence of methanol and acetone environment while parent hydroxyapatite Ca10(PO4)6(OH)2 shows only nominal change. Parent and Fe doped hydroxyapatite Ca1−xFex(PO4)6(OH)2 (0 ≤ x ≤ 0.3) samples were prepared by wet chemical method. All the samples are found in single phase using X‐ray diffraction (XRD), and they are crystallized in hexagonal structure. Fe K‐edge X‐ray absorption near edge structure (XANES) spectra show the presence of mixed‐valence states (Fe2+ and Fe3+) in Ca9.9Fe0.1(PO4)6(OH)2 sample while Fe is present in Fe3+ valence state in Ca9.7Fe0.3(PO4)6(OH)2 sample. Fe doped composition Ca9.9Fe0.1(PO4)6(OH)2 has shown the change in impedance (response) ~80% in presence of 50 ppm methanol concentration and ~238% for 500 ppm methanol concentration. Ca9.9Fe0.1(PO4)6(OH)2 has shown ~92% response for 50 ppm acetone concentration and ~537% response for 500 ppm acetone concentration. Analysis of response (change in impedance) using Freundlich adsorption isotherm equation has shown the physical and chemical type of adsorption for methanol while only physical adsorption for acetone is found in Ca9.9Fe0.1(PO4)6(OH)2. [ABSTRACT FROM AUTHOR]

The presence of alkali ions has reportedly improved the performance of CIGS/CZTS–based thin‐film solar cells. The out‐diffusion of the alkali ion, in particular, Na, from the glass substrate offers a facile scalable route of supplying the alkali ions during the growth of the absorber layer. In this work, we demonstrate the diffusion of different alkali ions (Li/Na/K) from composition tuned glasses with intentionally incorporated excess alkali ions into a thin Mo film, typically used as a bottom electrode in solar cells. We also evaluate the physical, mechanical, and thermal properties of the glasses for suitability as a substrate in thin‐film deposition. The out‐diffusion of alkali ions to the overlayer is found to be critically influenced by the composition and the local structure of the glasses. The Na ions exhibit the highest extent of diffusion among the alkali ions present in glass substrates, while that for the K‐ions is the lowest. For the glasses with mixed alkali ions, the presence of Li facilitated the out‐diffusion of Na, whereas K ions appear to inhibit the same. Differently with the existing reports, we show that the activation energy and the presence of Ca ions as additional modifiers play a crucial role in the transport mechanism of the ions. In addition, the synthesized glasses exhibit hardness of the order 5‐7 GPa, density ~2.55 g cm‐3. The glass transition temperature lies between 535 and 580°C and the coefficient of thermal expansion 8.5‐10 ppm/K, which is highly suitable for use as substrates in thin‐film solar cells. [ABSTRACT FROM AUTHOR]

Interface between layers of Fe and Hf is studied using magneto‐optical Kerr effect (MOKE) and soft X‐ray absorption spectroscopy (SXAS). Measurements as a function of the Fe layer thickness are done in a single sample by making use of a wedge‐shaped geometry for Fe layer sandwiched between two layers of Hf. SXAS measurements at the L‐edge of Fe provide evidence for interfacial alloying between Fe and Hf layers, with the thicknesses of the intermixed layers at Fe‐on‐Hf and Hf‐on‐Fe interfaces being 0.18 ± 0.05 and 0.27 ± 0.05 nm, respectively. Evolution of the MOKE hysteresis loop with Fe layer thickness gives an effective magnetic dead layer of 0.8 ± 0.1 nm at the two Fe/Hf interfaces together. Precise determination of the thickness of the intermixed layer and the magnetic dead layer using two independent techniques allows us to have a better insight into the interfacial magnetism and origin of magnetic dead layer at Fe/Hf interfaces. Present results suggest that the origin of the effective magnetic dead layer is partly due to modified magnetic moments of Fe and Hf in the intermixed regions and partly due to proximity‐induced magnetic moment in the interfacial Hf layers with its magnetic moment aligned antiparallel to the Fe layer. [ABSTRACT FROM AUTHOR]

Herein, the synthesis, structure, thermal stability, and magnetic properties of Ni4N thin films are studied. Ni4N is difficult to synthesize in the correct chemical order and stoichiometry due to unfavorable thermodynamics. During the synthesis of Ni–N thin films, it is found that the substrate temperature (Ts) is a critical parameter affecting the growth of a Ni4N phase. The Ni4N phase transforms into an amalgamation of [Ni+Ni3N] phases even if the Ts rises just above 300 K. These results elucidate a correlation between atomic diffusion and Ts. N self‐diffusion measurements carried out using secondary‐ion mass spectroscopy indicate that substantial N self‐diffusion is occurring at low Ts. A comparison of N self‐diffusion coefficients in Fe–N, Co–N, and Ni–N indicates that N self‐diffusion in Ni–N lies between that of Fe–N and Co–N and exhibits a greater correlation with the enthalpy of formation. A transformation from the cubic–to‐tetragonal deformation in the Ni4N crystal lattice as a function of increasing N concentration is evident from the X‐ray diffraction and X‐ray absorption near‐edge spectroscopy measurements. Magnetization measurements confirm a nonferromagnetic state of Ni4N at 300 K, which transforms into a ferromagnetic state at 15 K. [ABSTRACT FROM AUTHOR]

The correlation of several defects and optical and magnetic properties with Fe content in Zn1−xFexAl2O4 (0.01 ≤ x ≤ 0.40) nanocrystals has been scrutinized through X‐ray diffraction, O K‐edge X‐ray absorption near‐edge structure, FT–IR, diffuse reflectance, photoluminescence and electron spin‐resonance spectroscopies, and vibrating sample magnetometry. Increasing Fe content causes elongation in the octahedral units of the lattice, accompanied by distortion in the octahedral coordination. Fe introduces non‐radiative centres in the forbidden gap, thereby tuning the band gap from 4.37 to 3.88 eV and eliminating emission in the visible region. Zn vacancies are found to tail off, while , and FeAl× antisite defects increase in concentration with increasing Fe content. Inhomogeneous broadening of spin‐resonance signals infers strong spin‐lattice interactions of Fe3+ ions at distorted octahedral and non‐symmetric tetrahedral sites. A transition is observed from paramagnetism to superparamagnetism at higher Fe concentrations. A visual colour change from pearly white to orange–brown is observed in Zn1−xFexAl2O4 nanocrystals with increasing Fe content, revealing its potential candidature for pigments in the paint and dye industries. [ABSTRACT FROM AUTHOR]

Herein, preparation of Ag2ZnSnSe4 (AZTSe) thin films using physical vapor deposition followed by selenization in a quartz tube with rapid thermal process (RTP) is reported. The precursor stacks, [Sn/Se/ZnSe/Se/Ag/Se] × 4, are deposited onto the glass substrate at 100 °C using the combination of thermal and e‐beam evaporation methods. The post selenization of precursors is conducted at different temperatures (300–425 °C). The X‐ray diffraction and Raman spectra of the precursor films selenized at 400 °C reveal the formation of single‐phase AZTSe, exhibiting a kesterite structure with a preferred orientation along the (112) plane. These films show larger grains of ≈230 nm with the homogeneous distribution of Ag, Zn, Sn, and Se across the film thickness. The precursor films selenized at temperatures ≤400 °C show the fundamental absorption edge of AZTSe (Eg = 1.36–1.44 eV) as well as an additional adsorption edge (Eadd = 1.31–1.32 eV) corresponding to ZnSn + SnZn defect complex. The Hall effect measurement indicates n‐type conductivity irrespective of selenization temperature. For films selenized at 400 °C, the carrier concentration is decreased to 2.83 × 1011 cm−3 and results in a high mobility of 73.9 cm2(V s)−1, which is attributed to the reduction of SnZn defects. [ABSTRACT FROM AUTHOR]

W/B4C multilayers (MLs) consisting of ten layer pairs with varying boron carbide layer thicknesses have been investigated. The ML structures were characterized using grazing‐incidence hard X‐ray reflectivity (GIXR), resonant soft X‐ray reflectivity (RSXR), hard X‐ray photoelectron spectroscopy (HAXPES) and X‐ray absorption near‐edge spectroscopy (XANES). Depth‐resolved spectroscopic information on the boron carbide layer in W/B4C MLs was extracted with sub‐nanometre resolution using reflectivity performed in the vicinity of the B K‐edge. Interestingly, these results show that the composition of boron carbide films is strongly dependent on layer thicknesses. HAXPES measurements suggest that most of the boron is in the chemical state of B4C in the multilayer structures. XANES measurements suggest an increase in boron content and C—B—C bonding with increase in boron carbide layer thickness. [ABSTRACT FROM AUTHOR]

In the present study, surface and interface characterization of magnesium oxide (MgO) thin film is carried out by using non‐destructive soft X‐ray reflectivity and absorption technique. To get a further insight about the in‐depth and surface composition, secondary ion mass spectroscopy measurement is also carried out. The analysis of the reflectivity data indicates the presence of Mg‐Si‐O layer between the principal layer (MgO) and Si substrate interface. The secondary ion mass spectroscopy spectra corroborate well with the model assumed in the analysis of the reflectivity data. Combined soft X‐ray reflectivity‐total electron yield result confirms the presence of low‐density MgO on top of principal MgO layer. Total electron yield result confirms the rocksalt structure of the film and provides a glimpse of the electronic structure near the O‐K absorption edge. [ABSTRACT FROM AUTHOR]

Abstract: Mn and Co doped TiO2 thin films with varying doping concentrations have been prepared by r.f magnetron sputtering technique. Preliminary structural characterization of the samples have been carried out by Grazing Incidence X‐ray diffraction (GIXRD) measurements. Detail studies by X‐ray Absorption Spectroscopy (XAS), which comprises of both X‐ray Near Edge Structure (XANES) and Extended X‐ray Absorption Fine Structure (EXAFS) techniques, have been carried out on the samples at dopants (Mn,Co) and host (Ti) K‐edges to have an overall information on the local structures around the above atomic sites of the samples. The information obtained above have been corroborated by O K‐edge XANES, metal L‐edge XAS measurements and theoretical simulations of XANES spectra also. Finally room temperature ferromagnetism observed in the doped TiO2 samples has been explained on the basis of the above structural information. [ABSTRACT FROM AUTHOR]

Abstract unavailable. [ABSTRACT FROM AUTHOR]

The correlation of several defects and optical and magnetic properties with Fe content in Zn 1-x Fe x Al 2 O 4 (0.01 ≤ x ≤ 0.40) nanocrystals has been scrutinized through X-ray diffraction, O K-edge X-ray absorption near-edge structure, FT-IR, diffuse reflectance, photoluminescence and electron spin-resonance spectroscopies, and vibrating sample magnetometry. Increasing Fe content causes elongation in the octahedral units of the lattice, accompanied by distortion in the octahedral coordination. Fe introduces non-radiative centres in the forbidden gap, thereby tuning the band gap from 4.37 to 3.88 eV and eliminating emission in the visible region. Zn vacancies are found to tail off, while {\rm Fe}&#95;i^{\bullet \bullet \bullet}, {\rm Al}&#95;{\rm Zn}^\bullet and Fe Al × antisite defects increase in concentration with increasing Fe content. Inhomogeneous broadening of spin-resonance signals infers strong spin-lattice interactions of Fe 3+ ions at distorted octahedral and non-symmetric tetrahedral sites. A transition is observed from paramagnetism to superparamagnetism at higher Fe concentrations. A visual colour change from pearly white to orange-brown is observed in Zn 1-x Fe x Al 2 O 4 nanocrystals with increasing Fe content, revealing its potential candidature for pigments in the paint and dye industries.