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The effect of a slight A- and B-site cation nonstoichiometry on the structure, densification, and microwave dielectric properties of Ba(Mg1/ 3Ta2/3)O3 (BMT) was investigated. Magnesium and barium nonstoichiometric compositions based on Ba(Mg0.33 - x Ta0.67)O3 [x = −0.015, −0.010, −0.005, 0.0, 0.005, 0.010, 0.015, 0.020, 0.025, and 0.030] and Ba1 - x (Mg0.33Ta0.67)O3 [x = −0.015, −0.010, −0.005, 0.0, 0.0025, 0.005, 0.0075, 0.010, 0.015, 0.020, 0.025, and 0.030] were prepared using the conventional solid-state ceramic route. The lattice distortion and cation ordering were determined using X-ray diffraction technique. The phase composition and surface morphology were studied by EDX and scanning electron microscopy techniques, respectively. The sintered samples were characterized in the microwave frequency range using the resonance technique. It is found that a slight barium or magnesium deficiency can improve density, microwave dielectric properties, and cation ordering, while the addition of excess ions deteriorated them. The improvement in microwave dielectric properties was more pronounced in barium nonstoichiometric samples. Microwave dielectric properties of Ba0.9925(Mg0.33Ta0.67)O3 [εr = 24.7, τf = 1.2 ppm/°C, Quxf = 152 580 GHz] and Ba(Mg0.3183Ta0.67)O3 [εr = 25.1, τf = 3.3 ppm/°C and Quxf = 120 500 GHz] were found to be better than stoichiometric BMT [εr = 24.2, τf = 8 ppm/°C and Quxf = 100 500 GHz]. Raman spectroscopy was employed to study the effects of nonstoichiometry and related lattice distortions in BMT ceramics on their vibrational modes. Raman results clearly showed the 1:2 ordered structures of these materials with all active modes assigned. The spectra showed variations in the normal modes as a function of the composition. Also secondary phases contributed to the changes in the Raman spectra observed in compounds with x ≥ 0.02.

Two-dimensional materials play a vital role in the current electronic industry in the fabrication of devices. In the present work, we have exfoliated and stabilized the insulating hexagonal boron nitride (hBN) by means of a polymer-assisted liquid-phase technique. Further, the highly viscous ink of hBN was prepared, and its printability on various commercially available substrates was studied. The morphology of the printed patterns reveals the layered arrangement of hBN. The various electrical and dielectric characterizations, carried out on a metal–insulator–metal capacitor, testified its potential applications in various fields of printed electronics.

Homogeneously dispersed hybrid silica/syndiotactic polystyrene composites were investigated for low-κ dielectric applications. The composites were prepared by a solution blending method, and their microstructures were analyzed by SEM, TEM, and AFM. Crystallization and phase transformation behavior of sPS were investigated using differential scanning calorimetry and wide-angle X-ray diffraction. These composites exhibited improved thermal stability and reduced thermal expansion coefficients. Promising dielectric properties were observed for the composites in the microwave frequency region with a dielectric constant (κ = 1.95) and loss (tan δ = 10(-4)) at 5 GHz.

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Syndiotactic polystyrene aerogels with hierarchical micro, meso and macroporosity possess an ultra low dielectric constant very near to air.

A fast curing screen-printable ink formulation for MWCNT possessing excellent stability, adhesion strength, and electrical properties is reported.