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Although atomically precise polyhydrido copper nanoclusters are of prime interest for a variety of applications, they have so far remained scarce. Herein, this work describes the synthesis of a dithiophosphate‐protected copper(I) hydride‐rich nanocluster (NC), [Cu30H18{S2P(OnPr)2}12] (1H), fully characterized by various spectroscopic methods and single‐crystal X‐ray diffraction. The X‐ray structure of 1H reveals an unprecedented central Cu12 hollow icosahedron. Six faces of this icosahedron are capped by Cu3 triangles, the whole Cu30 core being wrapped by twelve dithiophosphate ligands and the whole cluster has ideal S6 symmetry. The locations of the 18 hydrides in 1H were ascertained by a single‐crystal neutron diffraction study. They are composed of three types: capping μ3‐H, interstitial μ4‐H (seesaw) and μ5‐H ligands (square pyramidal), in good agreement with the DFT simulations. The numbers of hydrides and ligand resonances in the 1H NMR spectrum of 1H are in line with their coordination environment in the solid state, retaining the S6 symmetry in solution. Furthermore, two new Se‐protected polyhydrido copper nanoclusters, [Cu30H18{Se2P(OR)2}12] (2H: R=iPr 3H: R=iBu) were synthesized from their sulfur relative 1H via ligand displacement reaction and their X‐ray structures feature the exceptional case where both the NC shape and size are fully conserved during the course of ligand exchange. DFT and TD‐DFT calculations allow understanding the bonding and optical properties of clusters 1H–3H. In addition, the reaction of 1H with [Pd(PPh3)2Cl2] in the presence of terminal alkynes led to the formation of new bimetallic Cu−Pd alloy clusters [PdCu14H2{S2P(OnPr)2}6(C≡CR)6] (4: R=Ph; 5: R=C6H4F). [ABSTRACT FROM AUTHOR]

A single-phase lead-free ferroelectric compound, Fe 1 / 2 (NaLi) 1 / 4 TiO3, is found at room temperature. The solid state reaction technique helps to process the sample at the calcination and sintering temperatures of 900 and 950 ∘ C for 4 h respectively. The desired phase and crystal structure formation of the prepared sample are confirmed by analysis of X-ray diffraction (XRD) data and are found to be in orthorhombic structure. The correlation among phase formation and physical properties has been established by using complex impedance spectroscopy (CIS) method over a wide range of frequencies (from 100 Hz to 1 MHz) and different temperatures (25–280 ∘ C). The overlap depressed semicircular arcs represent the association of grain and grain boundary effects in the material. Activation energy (E a) is noted to be 1 eV for the prepared sample. The frequency dependent ac conductivity is followed by Jonscher's universal power law. DC conductivity versus temperature graph also indicates the negative temperature coefficient of resistance (NTCR) behavior of the material. [ABSTRACT FROM AUTHOR]

The strontium-modified barium titanate ( Ba 0. 7 Sr 0. 3 TiO 3) ceramic was fabricated by high temperature compound reaction route. The pattern of X-ray diffraction confirms a single-phase compound with better crystallization. The dielectric properties (permittivity/loss) are investigated as a function of temperature and frequency. The relaxation mechanism and correlation with the physical properties are studied using complex impedance spectroscopy. The Nyquist plot shows the association of various effects (grain and grain boundary) by fitting electrical circuits at various temperature regions. This study tells the nature and conduction mechanism of the prepared sample. The Jonscher's universal power law is being followed by the frequency-dependent ac conductivity. [ABSTRACT FROM AUTHOR]

A structural study of ligand exchange on chalcogen‐passivated copper nanoclusters is far less developed. Herein, we report the synthesis of polyhydrido copper nanoclusters [Cu20H11{Se2P(OiBu)2}9] (2) passivated by Se‐donor ligands via ligand replacement reaction on [Cu20H11{S2P(OiPr)2}9] (1) with NH4[Se2P(OiBu)2]. In parallel to the synthesis of 2, cluster [Cu20H11{S2P(CH2CH2Ph)2}9] (4) was produced by the ligand exchange reaction on a new derivative of 1, that is [Cu20H11{S2P(OnPr)2}9] (3). Solid state structures of both clusters 2 and 4 were unequivocally established by single‐crystal X‐ray diffraction studies and cluster 4 epitomizes exceptional case to preserve both the shape and size of the nanocluster during the course of ligand exchange. Structurally precise cluster 2 is the second example where the copper hydride nanocluster is stabilized by Se‐donor ligands. The anatomy of 2 can be visualized as a twisted cuboctahedral Cu13 core, two triangular faces of which are capped by a Cu6 cupola and a single Cu atom along the C3 rotational axis. [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]

A single phase multiferroic magnetoelectric compound, (Sm 0.5 Li 0.5 )(Fe 0.5 V 0.5 )O 3 , is found at room temperature. This sample is fabricated using solid state reaction route. Analysis of the structural properties of the sample by X-ray diffraction method confirmed the fabrication of the desired compound with orthorhombic unit cell structure. Morphological property of the sample is recorded by field emission scanning electron microscopy (FE-SEM). Impedance spectroscopy is employed to determine the various electrical parameters such as dielectric constant, loss tangent, impedance, electric modulus, etc. at different temperature (RT–400 °C) within a frequency range of (1 kHz–1 MHz). Furthermore, the bulk resistance as function of temperature and J – E characteristic showed the semiconducting behavior of sample with negative temperature coefficient of resistance (NTCR) type nature of the compound. The M – H loop of this sample indicates the ferromagnetic nature with very low coercive field. A dedicated magnetoelectric set up is used to measure the ME coefficient as a function of magnetic field and found a significant ME coefficient of 2.99 mV Cm −1  Oe −1 at room temperature. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of lithium and molybdenum modified antimony ferrite (SbLi) 1/2 (Fe 2/3 Mo 1/3 )O 3 were carried out using solid-state reaction techniques. The preparation conditions and mass loss of the homogeneous mixture of required ingredients were decided based on thermal analysis (TGA). The formation of single-phase compound was confirmed by preliminary structural analysis using X-ray diffraction data. Electric properties of the material were studied in a wide temperature range (30–500 °C) at different frequencies (100 Hz–1 MHz) using impedance spectroscopy technique. The dc conductivity was found to obey Arrhenius relation suggesting the material to be of NTCR type. The activation energy calculated from the dc conductivity curve for grain and grain boundary effect is 0.60 and 0.47 eV respectively. The Jonscher’s universal power law governs the nature of ac conductivity of the material. Remnant polarization was found to be 0.86 (μC/cm 2 ). The magnetic measurements revealed weak remnant magnetization (0.01516 emu/g). [ABSTRACT FROM AUTHOR]