Modulating redox properties of solid-state ion-conducting materials using microwave irradiation.

The industrial adoption of low-carbon technologies and renewable electricity requires novel tools for electrifying unitary steps and efficient energy storage, such as the catalytic synthesis of valuable chemical carriers. The recently-discovered use of microwaves as an effective reducing agent of solid materials provides a novel framework to improve this chemical-conversion route, thanks to promoting oxygen-vacancy formation and O-surface exchange at low temperatures. However, many efforts are still required to boost the redox properties and process efficiency.

High-Resolution Detection of Rock-Forming Minerals by Permittivity Measurements with a Near-Field Scanning Microwave Microscope.

The identification of the minerals composing rocks and their dielectric characterization is essential for the utilization of microwave energy in the rock industry. This paper describes the use of a near-field scanning microwave microscope with enhanced sensitivity for non-invasive measurements of permittivity maps of rock specimens at the micrometer scale in non-contact mode. The microwave system comprises a near-field probe, an in-house single-port vectorial reflectometer, and all circuitry and software needed to make a stand-alone, portable instrument.

Detection of Anti-Counterfeiting Markers through Permittivity Maps Using a Micrometer Scale near Field Scanning Microwave Microscope.

This paper describes the use of microwave technology to identify anti-counterfeiting markers on banknotes. The proposed method is based on a robust near-field scanning microwave microscope specially developed to measure permittivity maps of heterogeneous paper specimens at the micrometer scale. The equipment has a built-in vector network analyzer to measure the reflection response of a near-field coaxial probe, which makes it a standalone and portable device.

Evidence of a new phase in gypsum-anhydrite transformations under microwave heating by dielectric analysis and Raman spectroscopy.

Mineral transformations of the gypsum-anhydrite system under microwave heating have been studied using in situ dielectric thermal analysis (MW-DETA) and Raman spectroscopy simultaneously. The dielectric properties of samples that were measured under microwave heating provided thorough information about the dynamics of the gypsum-anhydrite system transformations and its significance from the mineralogical point of view. In particular, the MW-DETA technique revealed a new intermediate phase with a γ-anhydrite structure.

Tribological and wear behaviour of alumina toughened zirconia nanocomposites obtained by pressureless rapid microwave sintering.

Dense alumina toughened zirconia nanocomposites (ATZ, 3Y-TZP with 20 wt% AlO) were densified by non-conventional microwave sintering technology at relatively low temperatures (1200 and 1300 °C). The sintering method and its effect on densification, microstructure, mechanical properties and tribological behaviour were investigated. The outcomes demonstrated that the density rose as the sintering temperature was higher, and therefore the mechanical properties were enhanced, reaching a maximum hardness (18.