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An Energy Scanning X-ray Absorption Fine Structure spectroscopy beamline has recently been installed and commissioned at BL-09 bending magnet port of INDUS-2 synchrotron source, Indore. The beamline uses an UHV compatible fixed exit double crystal monochromator (DCM) with two Si (111) crystals. Two grazing incidence cylindrical mirrors are also used in this beamline; the pre-mirror is used as a collimating mirror while the post mirror is used for vertical focusing and higher harmonic rejection. In this beamline it is possible to carry out EXAFS measurements both in transmission and fluorescence mode on various types of samples, using Ionization chamber detectors and solid state drift detector respectively. In this paper, results from first experiments of the Energy Scanning EXAFS beamline are presented.

In this work, we present structural, electronic, magnetic, mechanical and transport properties of equiatomic quaternary Heusler alloy, CoRhMnGe using both theoretical and experimental techniques. A detailed structural analysis is performed using X-ray diffraction(XRD) and extended X-ray absorption fine structure(EXAFS) spectroscopy. The alloy is found to crystallize in Y-type structure having space group F43m (# 216). The ab-initio simulation pedict half-metallic ferromagnetic characteristics leading to large spin polarization. The calculated magnetization is found to be in fair agreement with experiment as well as those predicted by the Slater-Pauling rule, which is a prerequisite for half-metallicity. The magnetic transition temperature(TC) is found to be ∼ 760 K. Measured electrical resistivity in the temperature range 2-400 K also gives an indication of half-metallic behavior. Simulated resistivity matches fairly well with those measured, with the temperature dependant carrier relaxation time lying in the range 1 − 2 fs. Effect of hydrostatic pressure on electronic structure, magnetic and mechanical properties are investigated in detail. The alloy is found to preserve half-metallic characteristics upto 30.27 GPa beyond which it transit to metallic phase. No magnetic phase transition is found to occur in the whole range of pressure. The system also satisfies the Born-Huang criteria for mechanical stability upto a limited range of pressure. All these properties make CoRhMnGe alloy promising for spintronics devices.

A multiple diglycolamide (DGA)-containing ligand having four DGA arms tethered to a tetraaza-12-crown-4 ring, viz. 2, 2′,2′′,2′′′-(((1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetrakis(2-oxoethane-2,1-diyl)) tetrakis (oxy)) tetrakis(N,N-dioctylacetamide) (T12C4ODGA), was synthesized and evaluated for the extraction of different actinide and lanthanide ions, viz. Am 3+ , Eu 3+ , Pu 4+ , Np 4+ , and UO 2 2+ . The extraction efficiency of the present ligand was found to be the highest reported so far, more specifically for the trivalent metal ions Am 3+ and Eu 3+ , when one considers the very low ligand concentration used in the present study, compared to that of the various previously reported multiple DGA-based ligands. The nature of the complexes formed during the extraction of Eu 3+ was investigated using time-resolved fluorescence (TRFS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. Both the solvent extraction and TRFS studies indicated the presence of 1:1 and 1:2 complexes during the extraction of Am 3+ and Eu 3+ having three inner-sphere water molecules in the 1:1 complex. Density functional theoretical (DFT) studies were performed on the Am 3+ and Eu 3+ complexes of both T12C4ODGA and an analogous compound having methyl groups in place of the n-octyl groups, and the DFT results of the T12C4ODGA nicely explain the extraction behavior of Am 3+ and Eu 3+ .

Graphitic carbon coated core/shell structured Ni/NiO nanoparticles were synthesized by a sol-gel type chemical precursor method and their structural, morphological and magnetic properties were evaluated. The synthesis method provides an improved and comparatively facile approach towards controlled growth of the composite structure of a metallic ferromagnetic (FM) core and an antiferromagnetic (AFM) metal oxide shell along with in situ growth of a supplementary surface functionalization layer of graphitic carbon. In addition, the process allows a precise control over the shape and size of this important class of core/shell type functional materials for a wide range of pertinent applications. The structural properties of the derived samples were studied with X-ray diffraction (XRD), X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), Raman spectroscopy, energy dispersive X-ray (EDX) analysis, and X-ray photoelectron spectroscopy (XPS). The microstructural features in the core/shell structured particles were evaluated using a scanning electron microscope (SEM) and a high resolution transmission electron microscope (HRTEM). Magnetic properties of the derived samples were studied using a vibrating sample magnetometer (VSM) in the 80-300 K temperature range. The surface functionalized Ni/NiO nanoparticles exhibit a distinctly enhanced magnetoresistance (MR), e.g., -10% at 290 K, than reported values in compacted Ni/NiO powders or composites.

High overpotentials required to cross the energy barriers of both hydrogen and oxygen evolution reactions (HER and OER) limit the overall efficiency of hydrogen production by electrolysis of water. The rational design of heterostructures and anchoring single‐atom catalysts (SAC) are the two successful strategies to lower these overpotentials, but realization of such advanced nanostructures with adequate electronic control is challenging. Here, the heterostructure of edge‐oriented molybdenum selenide (MoSe2) and nickel‐cobalt‐selenide (NiCo2Se4) realized through selenization of mixed metal oxide/hydroxide is presented. The as‐developed sheet‐on‐sheet heterostructure shows excellent HER performance, requiring an overpotential of 89 mV to get a current density 10 mA cm−2 and a Tafel slope of 65 mV dec−1. Further, resultant MoSe2@NiCo2Se4 is photochemically decorated with single‐atom iridium, which on electrochemical surface reconstruction displays outstanding OER activity, requiring only 200 and 313 mV overpotentials for 10 and 500 mA cm−2 current densities, respectively. A full cell electrolyzer comprising of MoSe2@NiCo2Se4 as cathode and its SAC‐Ir decorated counterpart as anode requires only 1.51 V to attain 10 mA cm−2 current density. Density functional theory calculation reveals the importance of rational heterostructure design and synergistic electronic coupling of single atom iridium in HER and OER processes, respectively.

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XANES study at Fe edge (a) and signature of ferromagnetism (b) of Zn1−xFexO nanoparticles.