Hydrothermally synthesized Ag:BiVO ₄ with a dendritic structure as an excellent electrode material for symmetric supercapacitors.

Magnetically separable Ag₃PO₄/NiFe₂O₄ (APO/NFO) composites were prepared by an in situ precipitation method. The photocatalytic activity of photocatalysts consisting of different APO/NFO mass ratios was evaluated by degradation of methylene blue (MB) under visible light irradiation. The excellent photocatalytic activity was observed using APO/NFO5 (5% NFO) composites with good cycling stability which is higher than that of pure Ag₃PO₄ and NiFe₂O₄. All the APO/NFO composites showed good magnetic behavior, which makes them magnetically separable after reaction and reusable for several experiments. Photoconductivities of pure and composite samples were examined to study the photoresponse characteristics. The current intensity greatly enhanced by loading NFO to APO. Furthermore, the photocatalytic performance of the samples is correlated with the conductivity of the samples. The enhancement in the photocatalytic activity of APO/NFO composites for MB degradation is attributed to the excellent conductivity of APO/NFO composites through the co-catalytic effect of NFO by providing accelerated charge separation through the n–n interface.

The strain-driven interfacial coupling between the ferromagnetic and ferroelectric constituents of magnetoelectric (ME) composites makes them potential candidates for novel multifunctional devices. ME composites in the form of thin-film heterostructures show promising applications in miniaturized ME devices. This article reports the recent advancement in ME thin-film devices, such as highly sensitive magnetic field sensors, ME antennas, integrated tunable ME inductors, and ME band-pass filters, is discussed. (Pb_1−xZr_x)TiO₃ (PZT), Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT), Aluminium nitride (AlN), and Al_1−xSc_xN are the most commonly used piezoelectric constituents, whereas FeGa, FeGaB, FeCo, FeCoB, and Metglas (FeCoSiB alloy) are the most commonly used magnetostrictive constituents in the thin film ME devices. The ME field sensors offer a limit of detection in the fT/Hz^1/2 range at the mechanical resonance frequency. However, below resonance, different frequency conversion techniques with AC magnetic or electric fields or the delta-E effect are used. Noise floors of 1–100 pT/Hz^1/2 at 1 Hz were obtained. Acoustically actuated nanomechanical ME antennas operating at a very-high frequency as well as ultra-high frequency (0.1–3 GHz) range, were introduced. The ME antennas were successfully miniaturized by a few orders smaller in size compared to the state-of-the-art conventional antennas. The designed antennas exhibit potential application in biomedical devices and wearable antennas. Integrated tunable inductors and band-pass filters tuned by electric and magnetic field with a wide operating frequency range are also discussed along with miniaturized ME energy harvesters.

Conventional thin-film processing techniques remain inadequate for obtaining superior dense ceramic thick films. The incompatibility of ceramic films prepared via other methods, such as screen printing, spin coating, and sputtering, is a major obstacle in the fabrication of thick film-based ceramic electronic components. The granule spray in vacuum (GSV) processes and aerosol deposition (AD) are important coating approaches for forming dense ceramic thick films featuring nanoscale crystallite structures at room temperature, which offer excellent material properties and facilitate cost-effective production. AD ceramic coatings require the acceleration of solid-state submicron ceramic particles via gas streams with a velocity of a few hundred meters per second, which are then wedged onto a substrate. This process is economical and particularly useful for the fabrication of piezoelectric thick film-based microactuators, energy harvesters, sensors, and optoelectronic devices. More recently, the GSV technique was improved to achieve more uniform and homogeneous film deposition after AD. This review article presents a detailed overview of the AD and GSV processes for piezoelectric thick films in terms of recent scientific and technological applications.