• S A Gangal

Articles written in Bulletin of Materials Science

• Effect of bulk and thin film dielectric overlay on the characteristics of microstrip rejection filter and simple microstriplines

The changes in the characteristics of microstrip rejection filter and simple microstriplines due to bulk and thin film dielectric overlay are reported in this paper. Al2O3 overlay both bulk and thin film increases theQ of the filter. All other overlays decrease theQ. TiO2 thin film shows improvement inQ whereas with bulk TiO2 the filtering property is not observed. The effect of overlays on simple lines is to reduce the transmission without much effect in the reflection.

• Microstrip losses with Al2O3 overlay

Microstriplines were coated with Al2O3 by chemical vapour deposition to get homogeneous thin film overlay. The paper reports the decrease in the total power loss in such microstrips. The frequency response from 2–6 GHz is studied for the overlay effect.

• Reactive deposition of Y1Ba2Cu3O7 −x superconductor films by pulsed laser ablation from an unreacted mixture of Y2O3, BaCO3 and CuO

Superconducting thin films of Y1Ba2Cu3 O7 −x have been deposited on (100) Y-ZrO2 substrates by pulsed excimer laser ablation from anunreacted mixture of Y2O3, BaCO3 and CuO. The films deposited at substrate temperature of 680°C and oxygen partial pressure of 200 mtorr were found to be superconducting with zero resistive transition temperature of 89 K and critical current density of over 3 × 105 A/cm2 at 77 K. These results are compared with those obtained by laser ablation from a sintered superconducting pellet.

• Study of $\beta$-phase development in spin-coated PVDF thick films

A study was conducted to ascertain the effect of variation in spin speed and baking temperature on $\beta$-phase content in the spin-coated poly(vinylidene fluoride) (PVDF) thick films ($\sim$4−25 $\mu$m). Development of $\beta$-phase is dependent on film stretching and crystallization temperature. Therefore, to study the development of $\beta$-phase in films, stretching is achieved by spinning and crystallization temperature is adjusted by means of baking. PVDF films are characterized using Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and scanning electronmicroscopy. It is observed that crystallization temperature lower than 60$^{\circ}$C and increase in spin speed increases the $\beta$-phasecontent in PVDF films. Crystallization temperature above 60$^{\circ}$C reduces $\beta$-phase content and increases α-phase content. It was also observed that viscosity of the PVDF solution affects the β-phase development in films at a particular spin speed.

• # Bulletin of Materials Science

Volume 43, 2020
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019