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This is the first report on the enhanced thermoelectric (TE) properties of novel reaction-temperature (TRe) and duration-induced Bi2S3-Bi nanocomposites synthesized using a facile one-step polyol method. They are well characterized as nanorod composites of orthorhombic Bi2S3 and rhombohedral Bi phases in which the latter coats the former forming Bi2S3-Bi core-shell-like structures along with independent Bi nanoparticles. A very significant observation is the systematic reduction in electrical resistivity ρ with a whopping 7 orders of magnitude (∼107) with just reaction temperature and duration increase, revealing a promising approach for the reduction of ρ of this highly resistive chalcogenide and hence resolving the earlier obstacles for its thermoelectric application potentials in the past few decades. Most astonishingly, a TE power factor at 300 K of the highest Bi content nanocomposite pellet, made at 27 °C using ∼900 MPa pressure, is 3 orders of magnitude greater than that of hot-pressed Bi2S3. Its highest ZT at 325 K of 0.006 is over twice of that of similarly prepared CuS or Ag2S-based nanocomposites. A significantly improved TE performance potential near 300 K is demonstrated for these toxic-free and rare-earth element-free TE nanocomposites, making the present synthesis method as a pioneering approach for developing enhanced thermoelectric properties of Bi2S3-based materials without extra sintering steps.

Even though doping small sized NCs is a challenging task, 2.7 nm sized tin oxide (SnO2) nanocrystals (NCs) are successfully doped with cobalt (Co). Studies are carried out in dilutely Co-doped SnO2 NCs, so as to avoid Co cluster formation and interference due to extrinsic effect. Co2+ ions are substitutionally doped in SnO2 lattice as seen from the d-d transitions in optical absorption spectra. Further x-ray photoelectron spectroscopic measurements also confirm Co2+ ionic state in SnO2 NCs. In view of the known fact that ferromagnetism in NCs arises due to different defects, Raman measurements are carried out. Raman spectra reveal presence of “in-plane” oxygen vacancies, which is also substantiated by photoluminescence spectra. Even though, Co-doping is not profoundly affecting the structure of SnO2 NCs, subtle ferromagnetic ordering observed in un-doped NCs get destroyed in Co-doped NCs. The present work reiterates the importance of Co-Co anti-ferromagnetic interaction and also indirectly supports the conjecture that oxygen vacancies adjacent with Co ions in SnO2 lattice in a necessary condition for realizing ferromagnetic ordering.

The effects of Ag nanoinclusions on thermoelectric properties of Ag2S semiconducting nanostructures, synthesized by a novel one-pot facile polyol method, have been investigated. The resulting produ...

Rare-earth chromates have always been of interest due to temperature-induced magnetization reversal and spin-reorientation phase transitions (SRPTs). In orthochromates containing magnetic rare earths, the spin configuration is supposed to undergo a characteristic changeover across the SRPT followed by an independent ordering of rare-earth moments leading to polar order. However, due to the presence of nearly 14% of highly neutron-absorbing isotope $^{149}\mathrm{Sm}$ in natural Sm based compounds, correct magnetic structure determination of ${\mathrm{SmCrO}}_{3}$ through neutron diffraction measurements has been a challenge. In the present study we investigate the pre- and post-SRPT spin configurations in well characterized ${\mathrm{SmCrO}}_{3}$ through time of flight neutron diffraction measurements carried out in zero field at the high-resolution high-flux WISH beam line of ISIS, in the United Kingdom. Magnetization measurement shows a canted antiferromagnetic phase transition at ${T}_{N1}=192\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, giving rise to a weak ferromagnetism, which undergoes a SRPT at 37 K. Rietveld analysis of the neutron powder diffraction data shows that below ${T}_{N1}=192\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ the ${\mathrm{Cr}}^{3+}$ and ${\mathrm{Sm}}^{3+}$ moments order in a $P{b}^{\ensuremath{'}}{n}^{\ensuremath{'}}m$:${\mathrm{\ensuremath{\Gamma}}}_{4}$(${\mathbit{G}}_{\mathbit{x}},{A}_{y},{F}_{Z};{F}_{Z}^{R}$) spin configuration with their tiny ferromagnetic components ${F}_{Z}$ and $\phantom{\rule{0.28em}{0ex}}{F}_{Z}^{R},$ giving rise to weak ferromagnetism. Below 37 K the $P{b}^{\ensuremath{'}}{n}^{\ensuremath{'}}m$:${\mathrm{\ensuremath{\Gamma}}}_{4}$(${\mathbit{G}}_{\mathbit{x}},{A}_{y},{F}_{Z};{F}_{Z}^{R}$) configuration transforms to $Pb{n}^{\ensuremath{'}}{m}^{\ensuremath{'}}:{\mathrm{\ensuremath{\Gamma}}}_{2}$(${F}_{x},{C}_{y},{\mathbit{G}}_{\mathbit{Z}};{F}_{x}^{R},\phantom{\rule{0.16em}{0ex}}{\mathbit{C}}_{\mathbit{y}}^{\mathbit{R}}$) as a result of continuous rotation of ${\mathrm{Cr}}^{3+}$ moments, while approaching SRPT below ${T}_{N1}$. At still lower temperatures the $Pb{n}^{\ensuremath{'}}{m}^{\ensuremath{'}}:{\mathrm{\ensuremath{\Gamma}}}_{2}$(${F}_{x},{C}_{y},{\mathbit{G}}_{\mathbit{Z}};{F}_{x}^{R},\phantom{\rule{0.16em}{0ex}}{\mathbit{C}}_{\mathbit{y}}^{\mathbit{R}}$) phase transforms to polar phases, either the $P{2}_{1}^{\ensuremath{'}}{2}_{1}^{\ensuremath{'}}{2}_{1}:{\mathrm{\ensuremath{\Gamma}}}_{26}$(${C}_{x},{\mathbit{G}}_{\mathbit{y}},{F}_{z};{\mathbit{C}}_{\mathbit{x}}^{\mathbit{R}},\phantom{\rule{0.16em}{0ex}}{A}_{y}^{R},\phantom{\rule{0.16em}{0ex}}{F}_{z}^{R}$) or the $P{n}^{\ensuremath{'}}a{2}_{1}^{\ensuremath{'}}:{\mathrm{\ensuremath{\Gamma}}}_{27}$(${F}_{x},{C}_{y},{\mathbit{G}}_{\mathbit{z}};{F}_{x}^{R},\phantom{\rule{0.16em}{0ex}}{\mathbit{C}}_{\mathbit{y}}^{\mathbit{R}},{G}_{z}^{R}$) phase, as a result of independent antiferromagnetic ordering of ${\mathrm{Sm}}^{3+}$ moments at ${T}_{N2}l4\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ through ${\mathrm{Sm}}^{3+}\text{\ensuremath{-}}{\mathrm{Sm}}^{3+}$ direct interaction. Our result of the transformation of ${\mathrm{SmCrO}}_{3}$ from ${\mathrm{\ensuremath{\Gamma}}}_{4}$ to ${\mathrm{\ensuremath{\Gamma}}}_{2}$ below SRPT is in contradiction with the ${\mathrm{\ensuremath{\Gamma}}}_{1}$(${A}_{x},{\mathbit{G}}_{\mathbit{y}},{C}_{Z};{C}_{z}^{R}$) spin configuration as reported in Tripathi et al. [Phys. Rev. B 96, 174421 (2017)]. This issue has been independently settled through ground-state energy calculation using spin-dependent density functional theory confirming the ${\mathrm{\ensuremath{\Gamma}}}_{2}$ spin configuration to be of lower energy as compared to that of the ${\mathrm{\ensuremath{\Gamma}}}_{1}$. The role of magnetocrystalline anisotropy in the occurrence of SRPT has been discussed.

Structural, morphological and Optoelectronic properties of Sb2Se3 film prepared by optimized screen-printing method is investigated and presented in this work. Sb2Se3 nanowires synthesized by microwave assisted solvothermal method along with ethylene glycol is used as the ink for the preparation of Sb2Se3 screen printed film. Structural analysis confirms the orthorhombic phase while the energy dispersive spectroscopy confirms the formation of Sb2Se3 composition. Crystallite size of the nanocrystalline powder (film) is found to be 60nm (104nm). The surface morphological properties as investigated from field emission scanning electron microscope (FESEM) show that the film is covered with nanowires of length 1-3µm and diameter 100-200nm uniformly distributed over the substrate but agglomerated uniformly as a spherical particle with diameter of ∼0.8µm. Interestingly, optoelectronic properties of the film and nanocrystalline powder show a band gap value of 1.19eV and 1.22eV respectively with an infinitesimal change in the band gap of the order of 0.03eV which is in correspondence with the morphological properties. Sb2Se3 being a potential material for solar cells, photodetectors and thermoelectric applications, this combination of fast and facile solvent-mediated microwave synthesis and screen-printing approach exhibits importance towards the wearable technology application for harvesting alternate electrical energy.

This is the first report on the enhanced thermoelectric (TE) properties of novel reaction-temperature (

We report a simple interface modified strategy to self-assemble the as-synthesized Au@Fe2O3 nano structures by facile chemical synthesis route on graphene substrate (AFG) fo r substrate mediated photo-catalytic dye degradation. The substrate modification, film formation, photo induced charge transfer mechanism and the physico-chemical properties of the AFG has been systematically analysed using different analytical techniques. The alteration in light absorption capacity and band gap of the hybrid with respect to the individuals have been observed using diffuse reflectance spectroscopy. Moreover, the broad absorption in the visible range and squeeze in band gap of the hybrid from 2.3 to 1.97 eV confirms the ability of the hybrid and the intention of hybridization for visible light-responsive photo-catalysis. Additionally, interesting superparamagnetic behaviour of the hybrid and its magnetic separation ability has been explored. Further, the applicability, repeatability and versatility of this AFG hybrid material in catalytic degradation of different dyes in presence of visible light have been analysed. This AFG catalyst exhibits excellent photocatalytic activity against the decolouration of the both cationic and anionic dyes. A systematic study in the photo-catalytic degradation behaviour, kinetic of degradation and the postulated mechanism has been proposed.

In this work, we studied amorphous carbon (a-C) thin films deposited using direct current (dc) and high power-impulse magnetron sputtering (HiPIMS) techniques. The microstructure and electronic properties reveal subtle differences in a-C thin films deposited by two techniques. While films deposited with dcMS have a smooth texture typically found in a-C thin films, those deposited with HiPIMS consist of dense hillocks surrounded by a porous microstructure. The density of a-C thin films is a decisive parameter to judge their quality. Often, x-ray reflectivity (XRR) has been used to measure the density of carbon thin films. From the present work, we find that the determination of density of carbon thin films, especially those with a thickness of few tens of nm, may not be accurate with XRR due to a poor scattering contrast between the film and substrate. By utilizing neutron reflectivity in time of flight mode, it has been shown that the density of carbon films can be measured more accurately. Prime novelty statement In this work, we have studied amorphous carbon (a-C) thin films prepared by direct current and high power impulse magnetron sputtering (dcMS and HiPIMS). We did precise density measurements using time of flight (ToF) neutron reflectivity (NR), a technique seldom used to study carbon thin films. We amply demonstrate limitation of x-ray reflectivity technique generally used for determination of density of thin carbon films. It is expected that our demonstration of NR in density determination of carbon thin film will turn out to be landmark for carbon film community and will certainly be helpful in enriching the related research work.

Li2FeSiO4/C aerogel is successfully prepared using a high-temperature, high-pressure supercritical drying method. The prepared Li2FeSiO4/C aerogel is annealed at optimum temperature. The structural information is obtained from Powder X-ray diffraction and Fourier transform infrared spectroscopy results. The Li2FeSiO4/C aerogel annealing temperature is fixed at 700 °C based on the Thermogravimetric and differential scanning calorimetry. The electrical conductivity of the Li2FeSiO4/C aerogel is calculated using alternating current impedance, and it is 1.4738 × 10-8 S cm-1. The presence of carbon and the formation of Li2FeSiO4 is confirmed through Raman analysis. The X-ray photoelectron spectroscopy elemental analysis reveals Si4+, Fe2+, Li+, and C with their respective binding energies. Field emission scanning electron microscopy and transmission electron microscopy images show the formation of randomly distributed tiny particles are linked together within a porous structure. The specific surface area of 59.037 m2 g-1 with an average pore diameter of 22.8 nm is measured through N2 adsorption/desorption isotherm analysis. The electrochemical performance of the Li2FeSiO4/C aerogel exhibits a discharge capacity of 140 mA.h g-1 at 100 mA g-1 current density over 130 cycles with 100% coulombic efficiency. Lithium-ion diffusion co-efficient (DLi+ = 2.63 × 10-8 cm2 s-1) is measured from electrochemical impedance spectroscopy.

In this communication, we identify some thermal-plasma assisted synthesis techniques for the alternative production of fusion relevant tungsten dust particles in bulk amounts, to allow for the statistically meaningful study of their hydrogen absorption properties. Fast, single step synthesis of fine particles in the α-tungsten phase was demonstrated, using a high heat flux device for sizes in the micrometer region and an experimental nanoparticle reactor for dust with nanometer sizes. Production of both equilibrium polyhedral and nonequilibrium spherulitic crystal shapes was demonstrated, dust morphologies similar to which were identified before in existing tokamaks and divertor simulator systems. Their hydrogen retention characteristics were measured by the Nuclear Resonance Reaction Analysis technique, which was found to be orders of magnitude higher compared to the same metal in the bulk form. The mesoporous crystals generated during high power, high pressure synthesis conditions were assumed to be responsible for the unusually high gas retention of the nanoparticle sample. It was concluded that non-equilibrium tungsten dust morphologies would be dominant in the high power fusion machines in the future, which may aggravate the hydrogen isotope retention issues further.

This work demonstrates the synthesis of fcc-Co derived from an isostructural Co4N phase. When deposited at high substrate temperature ( Ts) or thermal annealing ( Ta) above 573 K, the out-diffusion of N from fcc- Co4N occurs, leaving behind a high purity fcc-Co phase. Generally, Co grows in a hcp structure, and a hcp to fcc-Co transformation can be facilitated at high temperature or pressure. The proposed route by nitridation and diffusion of N not only brings down the transition temperature but an impurity present in the form of hcp-Co can be avoided altogether as well. Oriented Co4N(111) thin films were grown using a CrN(111) template on a quartz substrate using dc magnetron sputtering. Samples were grown at different Ts or room temperature grown Co4N samples were annealed at different Ta. Analysis using x-ray diffraction, N K-edge x-ray absorption, x-ray photoelectron, and secondary ion mass spectroscopy confirmed the formation of fcc- Co4N or fcc-Co phases. Furthermore, it was found that Co–N bonding and N concentration get significantly reduced at high Ts or Ta due to exceptionally high N self-diffusion taking place in Co4N. Magnetic measurements using ex situ and in situ magneto-optical Kerr effect showed differences in saturation behavior and coercivity of Co4N and fcc-Co samples. By combining structural, electronic, and magnetization measurements, it has been observed that a high purity fcc-Co can be conveniently derived from the isostructural Co4N aided by an exceptionally high N self-diffusion in Co4N.

The dominant role of trioctylphosphine (TOP) on the precise crystallite size and enhanced thermoelectric (TE) performance of the solution-grown Bi2Te3 nanorods annealed at 250 °C for 5 h under Ar gas flow and pelletization under 1 GPa pressure at 27 °C only has been demonstrated here. This has resulted in systematic reduction of crystallite size (D), emergence of a secondary phase BiTe with increasing TOP, and enhancement in thermopower but drastic drop in thermal conductivity due to atomic-scale control over the grain size and boundaries. The highest ZT and power factor (PF) obtained for nanorods with D = 40 nm are 1.95 and 1.4 times higher than those of D = 63 nm are due to the optimum intergrain energy barrier height for filtering of the charge/heat carriers. Remarkably, this enhanced ZT/PF is promisingly greater than those of the other more sophisticatedly solution-processed samples reported earlier. Moreover, the IR-active A1u modes in Raman spectra of nanorods of centrosymmetric Bi2Te3 have been observed for the first time with TOP-induced reduction of D confirming the breaking of crystal inversion symmetry due to the formation of sub-quintuples. Thus, this grain size alteration strategy for ZT improvement will open a new vista for further development of Bi2Te3-based efficient TE materials near room temperature.

Copper gallium selenide (CGS) semiconductor thin films are suitable for various optoelectronic devices due to their stoichiometry dependent properties. Tuning of electrical conductivity (0.5–90 S/cm) by compositional variations of CGS thin films prepared by reactive evaporation of the three elements under vacuum is presented here. This p-type absorber material withstands its conductivity type over the entire range of compositional variation. The structure, morphology, elemental composition, chemical states, electrical and optical properties of the thin films are characterized using techniques like X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, UV–visible absorption spectroscopy and Hall effect measurements. Optical studies of the films reveal a three-fold absorption from which crystal field splitting ∼0.06 eV and spin orbit splitting ∼0.09–0.17 eV are determined. The optical fundamental absorption edges of the films vary from 1.6 to 1.67 eV.

A novel deposition flux collimation technique has been explored in combination with glancing angle deposition geometry in radio frequency magnetron sputtering deposition technique with a motive to tailor the refractive index of silicon di-oxide thin film. In this technique, a collimating plate has been placed in parallel to the substrate at variable substrate to collimator distances (D SC = 4 mm, 6 mm and 9 mm) and the effect of D SC on various properties of the deposited film at different spatial locations on the substrate has been investigated. The use of such collimator was found to be highly effective in reducing the refractive index of the deposited film. A lowest refractive index of ~ 1.31 @ 550 nm of SiO 2 was achieved by using this novel collimation technique in combination with glancing angle deposition geometry which is not possible by glancing angle deposition geometry alone in the framework of non-directional deposition flux in magnetron sputtering technique. Variable angle spectroscopic ellipsometry (VASE) has been employed to accurately determine thickness and refractive index of the deposited films at various spatial locations of the sample. Ellipsometry data fitting model at different spatial locations has been verified by simulating the transmission spectrum based on the layer structure model obtained from ellipsometry modeling and then comparing it with that of the experimentally measured transmission spectra. For a given D SC an optimum location on the substrate surface was obtained to exhibit lowest refractive index. FTIR measurement showed no significant difference in bonding behavior of Si O among different representative spots of the deposited SiO 2 samples. AFM measurement on various spatial locations indicates a possible strong correlation between variation of refractive index and the grain size which is again affected by the degree of collimation and ad atom kinetic energy at various spatial locations.

The present manuscript reports vibrational spectra and optical studies of polycrystalline Fe

We have studied the partially ordered double perovskite (PODP) and spin-glass phase in $\mathrm{Sr}(\mathrm{M}{\mathrm{n}}_{1\ensuremath{-}x}{\mathrm{W}}_{x}){\mathrm{O}}_{3}$ ($x=0.20$ to 0.40) using neutron powder diffraction (NPD), muon spin relaxation (\ensuremath{\mu}SR), magnetic susceptibility (\ensuremath{\chi}), and x-ray photoelectron spectroscopy measurements. Structural studies reveal that $\mathrm{SrM}{\mathrm{n}}_{1\ensuremath{-}x}{\mathrm{W}}_{x}{\mathrm{O}}_{3}$ undergoes a quasicontinuous transformation from simple perovskite ($Pm\ensuremath{-}3m$) to PODP ($P{2}_{1}/n$) phase as $x$ increases. ${\ensuremath{\chi}}_{\mathrm{dc}}(T)$ and ${\ensuremath{\chi}}_{\mathrm{ac}}(T)$ measurements show a sharp cusplike peak at spin-glass transition ${T}_{g}$. The muon relaxation rate (\ensuremath{\lambda}) peaks at ${T}_{g}$ following a critical growth, given by $\ensuremath{\lambda}=\ensuremath{\lambda}(0){\ensuremath{\tau}}^{\ensuremath{-}w}[\ensuremath{\tau}=(T\ensuremath{-}{T}_{g})/{T}_{g}]$. No long-range magnetic order is observed in NPD below ${T}_{g}$. These measurements confirm a tunable spin-glass state of $\mathrm{SrM}{\mathrm{n}}_{1\ensuremath{-}x}{\mathrm{W}}_{x}{\mathrm{O}}_{3}$ for $0.2lxl0.4$. The spin-glass phase appears with the onset of $\mathrm{M}{\mathrm{n}}^{2+}$ cations, which induce competing ferro-antiferro interactions leading to exchange frustration. The ${T}_{g}$ decreases as the W content and $\mathrm{M}{\mathrm{n}}^{2+}$ concentration increase. Our results suggest that the spin-glass phase can be tuned through the relative concentration of 2+, 3+, and 4+ Mn ions.

PbS/polyvinylpyrrolidone (PVP) nanocomposite films with tunable band gap are synthesized by solid state in situ thermolysis. Precursor films are dip-coated on glass substrates from a methanolic solution of Pb2+–thiourea complex and PVP and then heated in air at 110 °C for 10 minutes to obtain shiny brown clear films of PbS/PVP. The formation of PbS nanoparticles in PVP matrix is confirmed by X-ray diffraction studies. The size of PbS nanoparticles varied from 2 to 8 nm depending of the weight fraction of the Pb2+–thiourea complex in the PVP. Transmission electron microscopy shows that the nanoparticles are spherical. The transmission spectra of the PbS/PVP films in the wavelength range of 300 to 2600 nm showed absorption edges near 900 nm and below due to the presence of PbS nanoparticles. The band gaps of PbS/PVP films, as determined from Tauc plots, varied from 0.8 to 1.92 eV as the weight fraction of the complex decreased from 82 to 36%. Fourier transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and 13C Nuclear Magnetic Resonance (NMR) studies reveal that there is strong interaction between PbS and PVP which limits the growth of the nanoparticles.

In this article, we quest for understanding the temperature dependent optical modes present in a-GexAs35 − xSe65 thin films. Strikingly, temperature dependent Raman spectra provide direct evidence of softening of AsSe3/2 pyramidal units and Se clusters at higher temperatures. In a stark contrast, GeSe4/2 corner and edge sharing tetrahedral units remain rigid against the temperature variation. Subsequently, FIR measurements at room temperature also provide significant insights on the optical modes in consistent with Raman data. In addition to that, our experimental results present fascinating optical features–thermally and compositionally tunable optical absorption spectra. We found that structural and optical parameters are closely related and help us in understanding the various physico-chemical properties which can eventually contribute to the field of optics and optoelectronics.

The deposition time dependence of optical, structural and morphological properties of thin as well as ultrathin Polytetrafluoroethylene (PTFE) sputtered films have been explored in the present communication. The films were prepared by RF magnetron sputtering under high vacuum condition, as a function of deposition time. The ellipsometry as well as X-ray reflectivity data show a drastic reduction in film thickness as the deposition time increases from 5 s to 10 s, possibly as a consequence of back sputtering. With subsequent deposition, back sputtering component decreases and hence, thickness increases with increase in deposition time. Atomic force microscopy (AFM) images show a slight change in growth morphology although roughness is independent of deposition time. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) measurements showed the presence of C C and CF x (x = 1–3) bonds in all the PTFE films. Supporting this, corresponding X-ray photoelectron spectroscopy (XPS) curves fitted for C-1s and F-1s peaks revealed a major contribution from CF 2 bonds along with significant contribution from CF 3 bonds leading to an F/C ratio of ∼1.5 giving hydrophobic nature of all the films.

The thin film of Inorganic–Organic (Hybrid) nanocomposite (NCs) based on polyvinyl alcohol (PVA) and lead sulfide (PbS) have been synthesized using solution casting technique with different concentrations of PbS. The prepared films were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy. The XRD confirms the presence of PbS nanoparticle (NPs) in PVA matrix. The morphology and thickness of NCs films were characterized by transmission electron microscopy and scanning electron microscopy, respectively. The optical transmittance (typically 220 nm) and photoluminescence spectra of NCs films were investigated in the wavelength range 300–2400 and 200–800 nm, respectively. The band gap of PbS NPs varies from 0.9 to 1.58 eV by altering the concentration of PbS.

Polycrystalline samples of Cox:TiSe2 have been prepared by solid state reaction and characterized by X-ray diffraction, SEM/EDX and XPS. Resistivity data indicate systematic changes upon the addition of cobalt with broad peaks due to Charge Density Wave (CDW) transitions. Clear features seen in thermoelectric power indicate the presence of CDW state in all the samples and are in line with the electrical transport data. Analysis based on a two band model for thermoelectric power could explain the results well. Addition of 1% Co in TiSe2 results in an enhancement of Weak Anti Localization (WAL) effect and supported by Hikami-Larkin-Nagaoka fit. Classical quadratic dependence along with an embedded weak localization (WL) feature at low fields is observed for 6% Co in TiSe2 that could be explained using a Khosla-Fischer fit due its close proximity for a magnetic transition.

Studies on thermal and transport properties of topologically interesting polycrystalline ZrTe5 down to 2 K and magnetic fields up to 14 T are reported here. Attempts have been made to explain the metal insulator transition-like features seen in magnetic fields, a behavior characteristic of ZrTe5. The maximum in relative magnetoresistance (MRmax) for a particular magnetic field with respect to the peak temperature, i.e., Tp(B), shows an activated behavior reminiscent of polaronic conduction seen upon chemical substitution like Hf in Zr. Magnetoresistance is well described by a small polaron hopping transport model in a systematic way for various fields. The estimated activation energies are in line with infrared spectroscopy as well as hole dominated thermopower supported by heat capacity measurements. The essential features of the analysis include square root dependence of magnetoresistance with the magnetic field possibly due to the weak antilocalization effect as well as T3/2 dependence on mobility, extracted from a simplified two-band model fit in magnetoresistance curves.

Al doping is used in transparent conducting CuInO2 (CIO:Al) thin films for producing bipolar electrical conductivity. The doped thin films of electrical conductivity ~2 to 4 S/cm and mobility 100 to 101 V/cm2 are deposited by oxygen plasma assisted reactive evaporation technique. The change in conductivity from n-to p-type with the variation in doping atomic percentage is confirmed by multiple techniques like hot probe, hall and Seebeck measurements. The as deposited amorphous films are found to assume 3R poly type delafossite structure after post air annealing at 673 K. The suitability of the doped films in transparent device fabrication is verified by construction and characterization of a diode with configuration FTO/n-CIO:Sn/p-CIO:Al/Ag.

Bi2Te3 nanomaterials were grown by microwave synthesis technique. Resistivity of the material shows semiconducting like nature which has been interpreted by thermally activated behavior in the high temperature range, three dimensional variable range hopping (VRH) mechanism in the middle range and combined effect of both electron-electron interaction and weak antilocalization(WAL) in the lower temperature regime from 10K to 2K. Full cycle magnetoresistance (MR) at 2K of the material exhibits WAL effect that evolves smoothly in to a linear positive magneto resistance (LPMR) up to 10K, thereafter to a simple parabolic nature with respect to magnetic fields. These features unequivocally provide evidence for the so called topological surface states (TSS) in Bi2Te3 even in its nanocrystalline form.

The dominant role of trioctylphosphine (TOP) on the particle size and various properties of CoO nanoparticle (NP) samples having Scherrer size in the range 9.4–42.8 nm is reported here; samples have been characterized in detail systematically. Remarkably, while nanosized CoO or CoO/Co nanocomposites with monoclinic or face-centered cubic (fcc) phase can be prepared depending on the synthesis conditions and particle size systematically decreases with increase in concentration of TOP, there is an increase in optical band gap and electrical resistivity with decrease in particle size. The highly semiconducting electrical resistivity is explained with the variable range hopping and small polaron hopping models that indicate in turn enhanced localized density of states, but decrease in Debye temperature (θD) as the particle size decreases. Curiously, 25.9 nm sample shows anomalous behaviour. Moreover, the silica-coated 9.4 nm CoO NP and bare 10.8 nm CoO NP samples exhibit ferromagnetism at 300 K even though their bulk counterpart is antiferromagnetic, with attractive indications of possible potential biomedical applications of the former.

A mutanase (α-1,3 glucanase)-producing bacterial strain of Paracoccus mutanolyticus was isolated from soil samples rich in cellulosic waste. Here, we report the whole-genome sequencing and annotation of P. mutanolyticus, which has a genome size of around 3.5 Mb and the potential to degrade water-insoluble α-1,3 glucans with an overall G+C content of 67.4%.

Government of India has been taking care to give equal status to women by enacting laws and by giving equal rights to women. But India is facing the severe problem of uneven ratio of male and female. A strong preference for sons is the root cause behind the uneven ratios, with some parents taking illegal gender tests to abort female foetuses. In much of India, a preference for male children is built into cultural ideology. Sons are traditionally viewed as the breadwinners who will carry on the family name and perform the last rites of the parents an important ritual in many faiths. Girls are often seen as a burden that parents can ill afford, largely due to the dowry of cash and gold jewelry that is required in marriage. The role of parents in upbringing their children and socializing them plays very important role in formation of strong society. On this background, researcher felt necessity to examine the role of social institutions in building the attitude and beliefs, How children learn about gender role . How child rearing and their socialization affects in understanding the gender differences . The objectives set for the study are 1. To understand the role of social institutions in child rearing and socializing. 2. To examine whether girls are getting equal treatment from their parents . For the present study, both primary and secondary data are collected. 80 school going girls having one or more brothers are interviewed by adopting snowball sampling method. Simple statistical tool such as percentage is used to analyze and interpret the primary data. Dr. Mrs. Neeta Uday Deshpande "A Study on Differential Socialization of Boys and Girls" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-3 , April 2018, URL: https://www.ijtsrd.com/papers/ijtsrd11479.pdf

Phase-change materials (PCM) show remarkable property-contrast from amorphous to crystalline phase that forms the basis for high-speed non-volatile memory device applications. Despite understanding the local structure and physical properties of these phases, a systematic study on the phase-change behavior is essential. Here, we used in situ UV–Vis–NIR spectroscopic measurements to study a systematic evolution of optical band gap (Eg) and the local disorder described by Tauc parameter (B), for the temperatures from 90 to 480 K on amorphous and cubic phases of Ge1Sb4Te7 thin films. It has been found that the Eg of amorphous phase decreases with increasing temperature from 90 to 400 K, while the disorder as exemplified by B, increases owing to thermal vibrations. At 420 K, a rapid decrease in the Eg from 0.47 to 0.33 eV and also a sharp reduction of ∼13% in the value of B1/2 is observed evidencing the signature of amorphous-to-cubic phase transition. Furthermore, the hexagonal phase is more disordered compared to cubic phase. The Raman results are consistent with optical measurements, which indicate that the degree of disorder reduces from amorphous to cubic phase, while hexagonal phase with an increased disorder is attributed to elongated bonds.

This paper reports rapid, continuous and carbon-nanotube free synthesis of carbon encapsulated magnetic nanoparticles by thermal-plasma expansion technique, which combines the typical advantages of high-temperature plasma assisted synthesis method with efficient particle-size control. Core nanocrystals were encapsulated with few layers of graphitized carbon, which could provide protection against both oxidation and intense chemical treatment. The average iron/iron-carbide nanoparticle diameter (7.7, 9 and 10 nm) and the width of the size distribution increased with pressure in the sample collection chamber, as a result of the decreasing quenching rate of the plasma jet. This also resulted in the smaller particles remaining frozen predominantly in the high-temperature γ-Fe phases, part of which was oxidized subsequently and eliminated preferentially during the purification process. All samples could be correlated with smooth variation of magnetic properties; saturation magnetization, remnant magnetization and coercive-field enhancing with increasing chamber pressure or average particle size. The low pressure synthesized sample with smallest average particle size approached super-paramagnetic behavior (saturation magnetization = 51.8 emu/g, ratio of remnant to saturation magnetization = 4.9 and coercive field = 52 Oe), which may be ideal for biomedical applications. High-pressure samples on the other hand have a higher saturation magnetization (76.3 emu/g) and coercive fields (123 Oe).

We report the first thermoelectric properties of Cu1−xAgxS, x = 0–0.75 nanocomposites, synthesized by using a facile polyol method. Systematic characterizations using powder XRD, Rietveld refinement of XRD, EDAX, XPS and Raman spectroscopy confirmed their single phase, hexagonal crystal structure with the space group P63/mmc, nominal elemental composition, valence states of the constituent elements and stoichiometric nature. The TEM images showing the CuS formation of nearly perfect hexagonal disk-like particles of average thickness 26.7 nm and breadth ranging in a few hundreds of nanometers with nanorods stacked from these hexagonal nanodisks (NDs) elongated along the c axis corroborate the FESEM images. Attributed to structural phase transition, an anomaly at 55 K is clearly observed in both the thermopower and Hall resistivity data. By increasing x, a systematic reduction in thermal conductivity was observed near 300 K. Consequently, a 50% enhancement in figure of merit was observed for Cu0.9Ag0.1S as compared to pure CuS at 300 K. These results therefore are expected to provide a new direction in improving ZT near 300 K.

Transport properties of the polycrystalline ZrTe5 showing a considerable positive Magneto-Resistance (MR) in the intermediate temperatures has been reported. Substantial shift of peak temperature by approximately 65 K with an applied magnetic field of 13.5 Tesla has been observed. Magneto resistance of this polycrystalline sample (∼100%) is comparable with its single crystalline counterpart reported in literature. The peak intensity scales with peak temperature and obeys reasonably the Dionne relationship that is a clear indication of polaron mediated conduction in this system. Magneto Resistance (MR) in this system is attributed to the two carrier polaronic conduction model similar to the Holstein’s approach. The results are further complemented with the Peak shift in magnetic field expected for a system having a fraction of localized carrier density. This observation places this famous thermoelectric material that displays a topological Dirac to Weyl transition in magnetic field in to the family of materials that have potential technological applications in the liquid nitrogen temperature range viz. 85-150 K.

Deposition of nanocomposite films of lead sulphide (PbS) nanoparticles in blend (1:1) of polyvinyl pyrrolidone (PVP) and Polyvinyl alcohol (PVA) by dip-coating from a precursor aqua-methanolic solution containing of Pb+2-TU complex (LTUC) is reported. To obtain nanocomposite films, solid precursor films are heated at about 110 °C in air for 10 mins to convert the LTUC in to PbS nanoparticles in PVP-PVA by in-situ thermolysis. PbS/PVP-PVA films with different loading of PbS was prepared by varying the concentration of LTUC in precursor solutions. The effect of LTUC on the microstructural, optical, thermal and electrical properties of the films was investigated. The X-ray diffraction of films confirms the presence of PbS nanoparticles in PVP-PVA matrix. The band gaps of PbS/PVP-PVA films varied from 1.8 to 0.8 eV as the concentration of LTUC varied from 0.0125 to 0.1 M due to formation of PbS nanoparticles. Transmission electron microscopy (TEM) shows that PbS nanoparticles are spherical with maximum diameter of 18 to 22 nm. The Fourier transformed infrared (FTIR) spectroscopy and X-Ray photoelectron spectroscopy (XPS) indicate the formation of hydrogen bond between –O–H group of PVA and –C = O group of PVP. However, PbS nanoparticles does not interact with either of the polymers. Thermogravimetric analysis (TGA) reveals that there was an improvement in thermal stability of PbS/PVP-PVA nanocomposites as compared to PVP-PVA blend. The dc conductivities of PVP-PVA and PbS/PVP-PVA(0.1 M) NC were found to be 3.2 × 10−6 S cm−1 and 14.2 × 10−6 S cm−1, respectively.