Magneto electric (ME) composites with the composition (x)Ni0.5Zn0.5Fe2O4+(1−x)Ba0.8Pb0.2Zr0.8Ti0.2O3 (BPZT—barium lead zirconate titanate), in which x varies as 0.0, 0.15, 0.30, 0.45, and 1.0 in molar ratio, were prepared by the conventional double sintering ceramic technique. The presence of two phases, namely ferrite (Ni0.5Zn0.5Fe2O4) and ferroelectric (Ba0.8Pb0.2Zr0.8Ti0.2O3), was confirmed by x-ray diffraction analysis. The DC resistivity was measured as a function of temperature, and the AC conductivity (σAC) as a function of frequency (100 Hz–1 MHz). From the experimental results, it is concluded that the conduction in these composites is due to small polarons. The relative dielectric constant with variation of frequency (in the range of 20 Hz–1 MHz) and temperature at four fixed frequencies (i.e. 1 kHz, 10 kHz, 100 kHz, and 1 MHz) was studied. The hysteresis behavior was studied to understand the magnetic properties such as saturation magnetization (Ms) and magnetic moment (μB). The static magneto electric voltage coefficient (dE/dH)H was measured as a function of applied DC magnetic field and it increases first and then decreases with increasing magnetic field. The variation of the ME response was explained in terms of the ferrite content, the resistivity of the composites and the intensity of the magnetic field. The maximum ME conversion factor, 698 μV cm−1 Oe−1, was observed for the composite with 30% ferrite+70% ferroelectric.

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The piezomagnetic ͑ferrite͒-piezoelectric ͑ferroelectric͒ composites with compositions ͑x͒ Ni 0.2 Co 0.8 Fe 2 O 4 + ͑1−x͒ Ba 0.8 Pb 0.2 Zr 0.8 Ti 0.2 O 3 ͓barium lead zirconate titanate ͑BPZT͔͒ in which x varies as 0.0, 0.15, 0.30, 0.45, and 1.0 mol % were prepared by conventional ceramic double-sintering method. The presence of constituent phases in the composites was confirmed by x-ray diffraction studies and the average grain size was calculated by using scanning electron microscopy. The dielectric constant ͑Ј͒ and loss tangent ͑tan ␦͒ were measured as a function of frequency in the frequency range 20 Hz-1 MHz. Variation of the dielectric constant and loss tangent with temperature at four fixed frequencies ͑1, 10, and 100 KHz and 1 MHz͒ was studied. The ac conductivity was studied to understand the conduction mechanism in terms of small polarons. The hysteresis behavior was studied to understand the magnetic properties such as saturation magnetization ͑M s ͒ and magnetic moment ͑ B ͒. The static magnetoelectric ͑ME͒ voltage coefficient was measured as function of applied dc magnetic field and variation in ME response has been explained in terms of the content of piezomagnetic phase and the intensity of applied magnetic field. The maximum ME conversion factor of 536 V / cm Oe was observed for 15% Ni 0.2 Co 0.8 Fe 2 O 4 +85% BPZT composite.

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Photo physical properties of fluorescent organic compounds give an immense improved knowledge on characteristics of excited state that is beneficial to devise innovate molecules and understand their performance in particular applications. Coumarin derivatives have been extensively investigated in this regard. This article narrates steady state fluorescence quenching measurements of a coumarin derivative namely 3-hydroxy-3-[2-oxo-2-(3-oxo-3H-benzo[f]chromen-2-yl)-ethyl]-1,3-dihydro-indol-2-one (3HBCD) in a binary mixture of acetonitrile and 1,4-dioxane. Aniline is used as quencher. Fluorescence intensity is large in acetonitrile and decreases as the percentage of 1,4-dioxane in the solvent mixture increases. With modest quencher concentration a deviation towards the x axis is noticed in the Stern-Volmer (S-V) plots. This downward curvature is interpreted as due to the presence of 3HBCD in different conformers in the lowest energy level. Ground state intramolecular hydrogen bonding formation is observed due to the conformational changes in the solute. Figured estimations of various quenching parameters recommend that, while dynamic quenching prompts linearity in S-V plot at lower quencher concentration, increasing quenching efficiency with increasing medium viscosity suggests that reaction is not entirely controlled by material diffusion. Stern-Volmer constant increases with decreasing medium dielectric constant.