Abstract Thermodynamic parameters were assessed for the MgO–FeOx system and combined with already available descriptions of ZrO2-FeOx ZrO2-MgO systems to calculate preliminary phase diagrams planning experimental investigations. Samples selected compositions heat treated at 1523, 1673 1873 K characterized using x-ray scanning electron microscopy energy dispersive spectroscopy (SEM/EDX). Experim...

The structure of high-temperature liquids is an important topic for understanding the fragility of liquids. Here we report the structure of a high-temperature non-glass-forming oxide liquid, ZrO2, at an atomistic and electronic level. The Bhatia-Thornton number-number structure factor of ZrO2 does not show a first sharp diffraction peak. The atomic structure comprises ZrO5, ZrO6 and ZrO7 polyhe...

Dental porcelain composites reinforced and toughened by 20 wt.% tetragonal zirconia (3Y-TZP) were processed by hot pressing at 1000°C. Two types of particles were tested: yttriastabilized zirconia (ZrO2–3%Y2O3) agglomerates and pre-sintered yttria-stabilized zirconia (ZrO2–3%Y2O3) particles. The composites as well as the reinforcing particles were analyzed by the means of optical and Scanning E...

Recrystallization and structural recovery in α-decay damage in zircon samples have been studied using Raman spectroscopy. Fifteen zircon samples with different degrees of radiation damage have been thermally annealed between 600 K and 1800 K for up to 28 days and 8 hours. The experimental results from this study reveal that recrystallization in the damaged zircon samples is a multi-stage proces...

Zirconium oxide (ZrO2) is one of the leading candidates to replace silicon oxide (SiO2) as the gate dielectric for future generation metal-oxide-semiconductor (MOS) based nanoelectronic devices. Experimental studies have shown that a 1–3 monolayer SiO2 film between the high permittivity metal oxide and the substrate silicon is needed to minimize electrical degradation. This study uses density f...

Strong visible emission under UV (320 nm) and IR (967 nm) excitation on ZrO2:Sm 3+ and ZrO2:Er 3+ nanophosphors were obtained and the concentration effect on the luminescence and crystalline structure is reported. Experimental results shows that phase composition depend on the ion concentration. The visible emission obtained under UV excitation is produced by the transitions G5/2 ! H5/2,7/2,9/2...

PURPOSE The purpose of this study was to investigate the possible radioactive potential of zirconium dioxide (ZrO2) dental ceramics. Such information is necessary since they became an integral part of routine prosthetic rehabilitations and devoid of scientific information about their radioactivity creates some concern in the dental community. METHODS Four different types of commercial ZrO2 ce...

Bleaching of Congo red catalyzed by ZrO2 nanoparticles was study under UV and sunlight irradiations. The nanoparticles of ZrO2 have been synthesized by controlled precipitation method. The concentration of ZrOCl2 and ammonia reactants and the calcinations temperature of ZrO2 were optimized for the control of nanoparticles size. Characterization of the prepared nanoparticles was studied by using...

The initial stages of growth of zirconia nanoparticles deposited on SiO2, Y2O3, and CeO2 substrates have been studied by the x-ray photoelectron spectroscopy peak shape analysis. ZrO2 was deposited by plasma decomposition of a volatile Zr OtBu 4 precursor. The electronic interactions at each particular interface formed have been followed by means of the modified Auger parameter of the deposited...

A quasi-analytic model has been developed to examine energy conversion during the microwave sintering of a ceramic that is surrounded by a susceptor. Low-loss ceramics, such as ZrO2, couple poorly with microwave radiation at low temperatures; however, because the dielectric loss usually increases rapidly as temperature increases, coupling improves dramatically at high temperatures. To improve h...