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When subjected to swift heavy ion (SHI) irradiation, a lattice acquires sufficient energy to induce desirable flaws in the material. In this study, the physiochemical properties of Sn-doped V2O5 (SVO) synthesized by a sol–gel process were thoroughly examined following irradiation with Ni+11 ions at 150 MeV energy and fluence of 2.51 × 1011 ions/cm2. The successful doping of Sn in V2O5 was confirmed by an increase in tensile strain, as revealed by the x-ray diffraction (XRD) spectrum, and the presence of characteristic peaks of constituent elements detected in the energy-dispersive x-ray (EDX) spectrum. Atomic force microscopy (AFM) and field-emission scanning microscopy (FESEM) images revealed an increase in surface roughness and transformation to an amorphous state, respectively. The Tauc plot indicated an increase in the electronic bandgap post-irradiation. Fourier transform infrared (FTIR) spectroscopy analysis revealed a peak shift in the fingerprint region indicating a change in the vibrational energy of the involved molecular bonds. These findings highlight the potential of SHI irradiation for the tuning of material properties, paving the way for a wide range of functional applications of the material. [ABSTRACT FROM AUTHOR]

In this work, the dielectric response of polycrystalline Ba3CoSb2O9 was studied as a function of temperature (30 to 900 °C) and frequency (10 Hz to 10 MHz). The triple perovskite Ba3CoSb2O9 was successfully synthesized and characterized for structural and dielectric properties. The Rietveld analysis of the X-ray diffractogram confirms the formation of a hexagonal phase with P63/mmc symmetry. This centrosymmetric 3(BaCo1/3Sb2/3O3) perovskite shows structural similarity to a prototypical non-centrosymmetric relaxor ferroelectric, PbMg1/3Nb2/3O3. The dielectric constant, ε', follows a non-Debye Cole–Cole relation and exhibits anomalous responses such as: (a) a thermally activated colossal dielectric constant (>105) and (b) a highly dispersive peak maximum (523–853 K). The real part of ac conductivity, σ′, also shows a change of approximately 6 orders in magnitude (10−8 to 10−2 S m−1). Validation of Jonscher's law and impedance (Nyquist plot) and modulus (M′′) analyses indicate that hopping polarization is the predominant thermally activated mechanism. Moreover, the large value of ε′ and its dispersion were found to be highly correlated with the underlying crystal structure and were attributed to the local ionic site ordering. The study suggests that the anomalous dielectric dispersion must have an intrinsic origin. [ABSTRACT FROM AUTHOR]

The most stable oxide of the vanadium oxide family is V2O5. A lot of research effort is focused on it because it has a multitude of functional applications. Here we report on how the heat treatment (600°C, 5h, air) affects the microstructure and hence, the band gap of V2O5. The V2O5 powders, initially obtained by simple thermal dissociation (500 °C, 3h, air) of ammonium metavanadate, followed by heat treatment of pellets; were studied. The structural and optical studies performed using X-ray diffraction (XRD), FESEM and UV-Vis techniques, provide uniquely interesting results which indicate the possibility of band gap tuning by controlling the microstructure. [ABSTRACT FROM AUTHOR]

The temperature dependence of magnetization and dielectric constant of polycrystalline Ba3NbFe3Si2O14 clearly indicates the presence of magnetically driven ferroelectric transition at 26 K, the Néel temperature TN, depicting its multiferroic behavior. The isothermal magnetization variation with the field both below and above TN however exhibits a hysteresis behavior with coercivity varying from 1600 Oe to 2500 Oe. These results combined with structural studies indicate the presence of multiple phases which are electronically and not structurally phase separated, similar to the phenomenon observed in magentoresistive perovskite compounds. [ABSTRACT FROM PUBLISHER]