Ferroelectric ε-WO3 nanoparticles were synthesized and stabilized above room temperature for the first time. A sensor based on this material was found to be highly sensitive and selective to acetone gas which will serve as a good candidate for diabetes diagnosis based on human breath analysis.

Titania (TiO 2 ) is an important electronic ceramic material for use in diverse applications such as gas sensors, catalysts, dielectrics, and ceramic membranes. TiO 2 exists as several polymorphic phases, most commonly as rutile or anatase. This paper investigates the microstructural evolution of anatasebased commercial TiO 2 powders, with an average size of 100 nm, at high temperatures. These powders transform to the rutile structure at 1000°C. The characteristics of the anataseto-rutile transformation have been studied using transmission electron microscopy analysis, and new information regarding the nature and mechanisms of this polymorphic reaction has been revealed.