Microwave-Driven Reduction Accelerates Oxygen Exchange in Perovskite Oxides.

Microwave-assisted oxide reduction has emerged as a promising method to electrify chemical looping processes for renewable hydrogen production. Moreover, these thermochemical cycles can be used for thermochemical air separation, electrifying the O generation by applying microwaves in the reduction step. This approach offers an alternative to conventional cryogenic air separation, producing pure streams of O and N.

Microwave-Driven Exsolution of Ni Nanoparticles in A-Site Deficient Perovskites.

Exsolution has emerged as a promising method for generating metallic nanoparticles, whose robustness and stability outperform those of more conventional deposition methods, such as impregnation. In general, exsolution involves the migration of transition metal cations, typically perovskites, under reducing conditions, leading to the nucleation of well-anchored metallic nanoparticles on the oxide surface with particular properties. There is growing interest in exploring alternative methods for exsolution that do not rely on high-temperature reduction via hydrogen.

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.

Non-invasive and continuous monitoring of the sol-gel phase transition of supramolecular gels using a fast (open-ended coaxial) microwave sensor.

An open coaxial re-entrant microwave sensor has been used for the non-invasive and continuous monitoring of the sol-gel transition of physical gels characterized by different gelation mechanisms, solvents, compositions, and stabilities. Comparison of measurements by differential scanning calorimetry allowed the identification of the phase transition by a change in the dielectric properties of the material over time.