The discovery of (BaxCa1-x)(ZryTi1-x)O3 lead-free ceramics drawn a lot of attention to those novel materials because of their excellent piezoelectric properties. However, quite a little attention has been paid to other features of the material. This article reports a wide range of research, including composition, structure and microstructure, dielectric response and impedance spectroscopy in order to systematize and expand knowledge about this peculiar ceramics and strontium doping effect on its properties. In order to test that influence a series of samples with various strontium concentration, precisely the admixtures of 0.02, 0.04 and 0.06 mol% were prepared, as well as basic ceramics to compare obtained results.

Tin dioxide (SnO2) is an n-type semiconductor and has useful characteristics of high transmittance, excellent electrical properties, and chemical stability. Accordingly, it is widely used in a variety of fields, such as a gas sensor, photocatalyst, optoelectronics, and solar cell. In this study, SnO2 films are deposited by thermal atomic layer deposition (ALD) at 180°C using Tetrakis(dimethylamino)tin and water. A couple of 5.9, 7.4 and 10.1nm-thick SnO2 films are grown on SiO2/Si substrate and then each film is annealed at 400°C in oxygen atmosphere. Current transport of SnO2 films are analyzed by measuring current – voltage characteristics from room temperature to 150°C. It is concluded that electrical property of SnO2 film is concurrently affected by its semiconducting nature and oxidative adsorption on the surface.

In this study, lead-free 0.94 Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-BT) compositions at morphotropic phase boundary were successfully synthesized by solid-state reaction method. The effects of the particle size for various milling time (12-24-48 hours) and sintering temperatures (1100-1125-1150-1175oC for 2h) on the electrical properties of the NBT-BT ceramics were evaluated. Experimental results showed that particle size and sintering temperatures significantly affect the electrical properties of NBT-BT ceramics. The particle size of the ceramic powders decreasing while milling time increases to 48 hours. Particle size values for 0, 12, 24 and 48 hours (h) milled powders were measured as nearly 1.5 µm, 1 µm, 700 nm, and 500 nm respectively. The bulk density enhanced with increasing sintering temperature and showed the highest value (5.73 g/cm3) at 1150oC for 48h milled powder. Similarly, the maximum piezoelectric constant (d33) = 105 pC/N, electromechanical coupling coefficient (kp) = 25.5% and dielectric constant (KT) = 575 were measured at 1150oC for 48 h milled powder. However, mechanical quality factor (Qm) was reduced from 350 to 175 with decreasing particle size. Similarly, remnant polarization was dropped by decreasing powder particle size from 56 μC/cm2 to 45 μC/cm2.

In this work, we present an extensive investigation of the effect of Al2O3 decoration on the morphological, structural and opto-electronic properties of a porous Si (Sip)/Cr2O3 composite. The Sip layers were prepared by the anodization method. Al2O3 and Cr2O3 thin films were deposited by physical vapour deposition. The morphological and micro-structural properties of Sip/Cr2O3/Al2O3 were studied using the scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction techniques. It was found that Al2O3 decoration with different concentration strongly affects the Sip/Cr2O3 microstructure mainly at the level of porosity. Variable angle spectroscopic ellipsometry demonstrates a strong correlation between optical constants (n and k) of Sip/Cr2O3/Al2O3 and microstructure properties. Dielectric properties of Sip/Cr2O3/Al2O3 such as electrical conductivity and conduction mechanism were explored using impedance spectroscopy over the temperature interval ranging from 340 to 410°C. A semiconductor to the metallic transition has been observed at high frequency.