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Atomically precise thiolate-protected coinage metal nanoclusters and their alloys are far more numerous than their selenium congeners, the synthesis of which remains extremely challenging. Herein, we report the synthesis of a series of atomically defined dithiophosph(in)ate protected eight-electron superatomic palladium silver nanoalloys [PdAg20{S2PR2}12], 2a–c (where R = OiPr, a; OiBu, b; Ph, c) via ligand exchange and/or co-reduction methods. The ligand exchange reaction on [PdAg20{S2P(OnPr)2}12], 1, with [NH4{Se2PR2}12] (where R = OiPr, or OnPr) leads to the formation of [PdAg20{Se2P(OiPr)2}12] (3) and [PdAg20{Se2P(OnPr)2}12] (4), respectively. Solid state structures of 2a, 2b, 3 and 4 unravel different PdAg20 metal frameworks from their parent cluster, originating from the different distributions of the eight-capping silver(I) atoms around a Pd@Ag12 centered icosahedron with C2,D3,Th and Th symmetries, respectively. Surprisingly ambient temperature crystallization of the reaction product 3 obtained by the ligand exchange reaction on 1 has resulted in the co-crystallization of two isomers in the unit cell with overall T (3a) and C3 (3b) symmetries, respectively. To our knowledge, this is the first ever characterized isomeric pair among the selenolate-protected NCs. Density functional theory (DFT) studies further rationalize the preferred geometrical isomerism of the PdAg20 core. Atomically and structurally precise silver nanoclusters hold great potential for catalytic and optoelectronic applications. Here, the authors synthesize and characterize a series of atomically defined dithio- and diselenophosphate-protected eight-electron superatomic palladium-doped silver nanoclusters, including an unprecedented pair of selenolate-protected isomers. [ABSTRACT FROM AUTHOR]

In the present era, global challenges are focused to meet the security of energy due to excessive energy demands. The coal and petroleum-based fossil fuels are soon fading out due to current energy-generating units; hence, the energy from renewable energy sources becomes an alternative medium and new scientific investment. Research is carried out to boost the efficiency of these devices. The multifunctional materials having superior properties are the need of the hour to provide insight towards producing low-cost energy devices. A perovskite having the chemical formula Bi1/2(Na1/4Li1/4)TiO3 (BNLTO) is synthesized using a solid-state reaction. The standard techniques were used to investigate the structural and electrical characterizations at various experimental conditions. The X-ray diffraction (XRD) spectra elucidated the presence of an orthorhombic symmetry in the synthesized sample. The high dielectric constant and low loss factor is evolved at various frequencies and temperatures. The Nyquist plot depicts the association of the combined effect of grain and grain boundary. The activation energies evaluated from the loss and modulus spectrum are noted as ~ 1.26 eV and 0.81 eV, respectively. The charge carriers contribute to the conduction mechanism at high temperature. Finally, a poled piezoelectric energy harvester is fabricated to check its capabilities for the conversion of small impact from hand palm into electrical energy. [ABSTRACT FROM AUTHOR]

In this communication, the detailed analysis of structural (including microstructural) and electrical (dielectric, impedance, conductivity, and modulus) features of a perovskite Li1/2Bi1/2TiO3 are reported. The compound is prepared by a high-temperature solid-state reaction technique. From X-ray diffraction, the crystal structure is fully satisfied with the monoclinic system of the material. Both dielectric permittivity and loss tangent of the pellet sample is scanned and analyzed in extensive temperatures (30–500 °C) and frequencies (100 Hz–1 MHz). Dielectric anomaly is detected at a particular temperature of 109 °C that may be associated with the ferroelectric-paraelectric phase transition. Through the Nyquist diagram, the presence of grains and grain boundary effect in the compound is detected. The observed non-Debye type of relaxation feature is confirmed through the complex impedance spectroscopy. Impedance analysis suggests that the grain resistance reduces with the rise of operating temperature, showing the negative temperature coefficient of resistance (NTCR) nature. Also, the non-Debye type of relaxation phenomenon is established from the modulus spectroscopy analysis. The significant result infers that this compound may be utilized for different high-temperature applications. [ABSTRACT FROM AUTHOR]

Relaxation mechanism, conductivity and magnetoelectric properties of (Nd1/2Li1/2)(Fe2/3Mo1/3)O3 multiferroic have been investigated systematically. This material was synthesized by a solid-state reaction route. Thermogravimetric analysis is enforced to perceive the percentage of weight change with rise in temperature in order to obtain the calcination temperature of the material. The preliminary structural study using X-ray diffraction data reveals the orthorhombic structure of the material. The complex plot of impedance data helped to distinguish the involvement of grain as well as grain boundary effects towards the overall electrical properties of the compound. Temperature-dependent electrical conductivity plots exhibit the presence of thermally activated conduction mechanism of the compound. The magnetic field dependence of magnetization (M–H loop) showed the presence of ferromagnetic nature of the material. The value of magnetoelectric coupling coefficient of prepared material is found to be 2.7 mV Cm−1 Oe−1. [ABSTRACT FROM AUTHOR]

In the present communication, studies of some physical properties (i.e., crystal data, permittivity, impedance, electrical cobnduction and magnetic) of a multiferroic material with a chemical composition (SmLi)1/2(Fe2/3Mo1/3)O3 have been reported. Thermogravimetric analysis of the compound, prepared by cost effective ceramic technology processing, was executed to check the mass loss as well as the required decomposition temperature of the ingredients. An analysis of X-ray spectra or pattern suggests that the crystallization phase or cystal system of the compound at room temperature is orthorhombic. The broad studies of dielectric properties {relative dielectric constant (εr), and tangent loss (tan δ)} display their independence of temperature and frequency in the rage of (30-375 °C) and (1 kHz-1 MHz) respectively. The impedance spectroscopic technique has provided a considerable significant information regarding the grain, grain boundary contribution within the sample and relaxation mechanism of the compound. The occurrence of negative temperature coefficient behaviour (NTCR) is depicted by the further analysis of impedance parameters. The frequency-temperature dependence of conductivity follows the Johnson’s power Universal law. The Arrhenius plot (i.e., variation of electrical conductivity with temperature) is used to calculate the activation energy. Analysis of magnetization (M-H) loop shows weak ferromagnetism of the compound. The material possesses significantly high magnitude of magnetoelectric coefficient of 3.0 mV Cm− 1 Oe− 1. [ABSTRACT FROM AUTHOR]

The bulk ceramics bearing chemical formula BiFeO3 and (BiLi)1/2(Fe2/3Mo1/3)O3 (abbreviated as BFO and BLFMO respectively) are synthesized using mixed oxide route. The physical properties (structural, dielectric, electric and magnetic) are tailored in Li and Mo co-doped BiFeO3. The phase evolution suggests that there is transformation from rhombohedral (pure BFO) to orthorhombic (BLFMO). Micro-structural suggests that due to co-doping the size of the grain is smaller than BFO. The dielectric properties of both BFO and BLFMO measure with an LCR meter varying the frequency (102–106 Hz) and temperature (30–375 °C). The leakage current decreases in BLFMO. The magnetic hysteresis loop owing weak ferromagnetism is depicted for Li and Mo co-doped BFO. The fabricated material will be base for various applications like filter and buffering. [ABSTRACT FROM AUTHOR]

The bulk ceramics bearing chemical formula BiFeO3 and (BiLi)1/2(Fe2/3Mo1/3)O3 (abbreviated as BFO and BLFMO respectively) are synthesized using mixed oxide route. The physical properties (structural, dielectric, electric and magnetic) are tailored in Li and Mo co-doped BiFeO3. The phase evolution suggests that there is transformation from rhombohedral (pure BFO) to orthorhombic (BLFMO). Micro-structural suggests that due to co-doping the size of the grain is smaller than BFO. The dielectric properties of both BFO and BLFMO measure with an LCR meter varying the frequency (102–106 Hz) and temperature (30–375 °C). The leakage current decreases in BLFMO. The magnetic hysteresis loop owing weak ferromagnetism is depicted for Li and Mo co-doped BFO. The fabricated material will be base for various applications like filter and buffering. [ABSTRACT FROM AUTHOR]

A new polycrystalline ceramic sample of (Sb1/2Na1/2)(Fe2/3Mo1/3)O3 is formed by cheap mixed oxide processing technique. The mass loss and the calcination temperature of the sample are optimized by thermogravimetric analysis and repeated firing. The formed sample crystallizes in the orthorhombic crystal structure at room temperature depicted from the X-ray diffraction spectra. The dielectric relaxation, impedance and modulus analysis of the sample have been analyzed in various temperature and frequency range. The dielectric parameters of the sample depend on frequency and temperature and with an increment in temperature the relaxation time falls. Impedance spectroscopy analysis predicts the association of grain and grain boundary resistance. The short and long-range mobility of the charge carriers are illustrated by the modulus plot. Ac conductivity is seen to be temperature and frequency dependent and hopping of the charge carriers is also observed at high temperature. Further, the universal power law is followed by ac conductivity mechanism. [ABSTRACT FROM AUTHOR]

A new polycrystalline ceramic sample of (Sb1/2Na1/2)(Fe2/3Mo1/3)O3 is formed by cheap mixed oxide processing technique. The mass loss and the calcination temperature of the sample are optimized by thermogravimetric analysis and repeated firing. The formed sample crystallizes in the orthorhombic crystal structure at room temperature depicted from the X-ray diffraction spectra. The dielectric relaxation, impedance and modulus analysis of the sample have been analyzed in various temperature and frequency range. The dielectric parameters of the sample depend on frequency and temperature and with an increment in temperature the relaxation time falls. Impedance spectroscopy analysis predicts the association of grain and grain boundary resistance. The short and long-range mobility of the charge carriers are illustrated by the modulus plot. Ac conductivity is seen to be temperature and frequency dependent and hopping of the charge carriers is also observed at high temperature. Further, the universal power law is followed by ac conductivity mechanism. [ABSTRACT FROM AUTHOR]

Low magnetic property is one of the major disadvantages of bismuth ferrite which limits its industrial utility. We have substituted bismuth from bismuth ferrite by antimony to solve the limitations of the material. Polycrystalline samples of SbFeO3 and BiFeO3 are prepared by solid-state reaction technique. Crystal structure investigation of both the compounds are carried out by X-ray diffraction (XRD). The crystallite sizes obtained from XRD data are 49 nm for SbFeO3 and 62 nm for BiFeO3. The impedance and dielectric studies of the materials are carried out at various frequency (102-106 Hz) in a wide temperature range (30-475 °C). Dc conductivity and ac conductivity of both the materials are explained by Arrhenius relation and Jonscher’s universal power law, respectively. Leakage current of SbFeO3 is found to be large compared to BiFeO3. [ABSTRACT FROM AUTHOR]

Abstract : Treatment of nido-[1,2-(Cp*Ru)2(μ-H)2B3H7], 1 with five equivalents of Te powder led to the isolation of diruthenium pentalene analogue [(Cp*Ru){(Cp*Ru)2B6H14}(RuCp*)], 2 and a metal indenyl complex [(Cp*Ru)2B2H6C6H3(CH3)], 3. The [(Cp*Ru)2B6H14] fragment in 2 may be considered as a true metal-boron analogue of η5-η5-pentalene ligand (C8H6) and [(Cp*Ru)B2H6C6H3(CH3)] fragment in 3 is an analogue of η5-indenyl ligand. The solid-state X-ray structures were unambiguously determined by crystallographic analysis of compounds 2 and 3. Further, the density functional theory (DFT) calculations were performed to investigate the bonding and the electronic properties of 2a (Cp analogue of 2). The frontier molecular orbital analysis of both 2a and 2b (Cp analogue of [(Cp*Ru)B8H14(RuCp*)]) reveals a lower HOMO-LUMO gap indicating less thermodynamic stability.Graphical Abstract: SYNOPSIS Treatment of nido-[1,2-(Cp∗Ru)2(μ-H)2B3H7] with Te powder led to the isolation of diruthenium pentalene analogue [(Cp*Ru){(Cp*Ru)2B6H14}(RuCp*)] and a metal indenyl complex [(Cp*Ru)2B2H6C6H3(CH3)]. [ABSTRACT FROM AUTHOR]