This study investigates the structural and catalytic properties of pure and Sr-doped LaCoO and LaFeO thin films for potential use as resistive gas sensors. Thin films were deposited via pulsed laser deposition (PLD) and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), nanoindentation, and scratch tests. XRD analysis confirmed the formation of the desired perovskite phases without secondary phases. XPS revealed the presence of La, Co/Co, Fe/Fe, and Sr oxidation states. SEM and AFM imaging showed compact, nanostructured surfaces with varying morphologies (shape and size of surface irregularities) depending on the composition. Sr doping led to surface refinement and increased nanohardness and adhesion. Transmission electron microscopy (TEM) analysis confirmed the columnar growth of nanocrystalline films. Sr-doped LaCoO demonstrated enhanced sensitivity and stability in the presence of NO gas compared to pure LaCoO, as evidenced by electrical resistivity measurements within 230 ÷ 440 °C. At the same time, it was found that Sr doping stabilizes the catalytic activity of LaFeO (in the range of 300 ÷ 350 °C), although its behavior in the presence of NO differs from that of LaCo(Sr)O-especially in terms of response and recovery times. These findings highlight the potential of Sr-doped LaCoO and LaFeO thin films for NO sensing applications.
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http://dx.doi.org/10.3390/ma18051175 | DOI Listing |
Adv Mater
March 2025
Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS, UMR 7504, Strasbourg, F-67000, France.
2D van der Waals materials and their heterostructures are a fantastic playground to explore emergent phenomena arising from electronic quantum hybridization effects. In the last decade, the spin-dependant hybridization effect pushed this frontier further introducing the magnetic proximity effect as a promising tool for spintronic applications. Here the uncharted proximity-controlled magnetoelectric effect in EuO/graphene heterostructure is unveiled.
View Article and Find Full Text PDFMaterials (Basel)
March 2025
Faculty of Metals Engineering and Industrial Computer Science, AGH University of Krakow, al. Mickiewicza 30, 30-059 Krakow, Poland.
This study investigates the structural and catalytic properties of pure and Sr-doped LaCoO and LaFeO thin films for potential use as resistive gas sensors. Thin films were deposited via pulsed laser deposition (PLD) and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), nanoindentation, and scratch tests. XRD analysis confirmed the formation of the desired perovskite phases without secondary phases.
View Article and Find Full Text PDFMaterials (Basel)
February 2025
Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
We investigated patterns formed during the polymerization process of bifunctional monomers in a liquid crystal for both large polymer concentrations (polymer-dispersed liquid crystals, PDLC) and small concentrations (polymer-stabilized liquid crystals, PSLC). The resulting experimental patterns are reminiscent of Voronoi diagrams, so a reverse Voronoi algorithm was developed that provides the seed locations of cells, thus allowing a computational reproduction of the experimental patterns. Several metrics were developed to quantify the commonality between the faithful experimental patterns and the idealized and generated ones.
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February 2025
Centro de Química-Vila Real, CQ-VR, Chemistry Department, Escola de Ciências da Vida e do Ambiente (ECVA), University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal.
This work explores the deposition of hexagonal (-) LuMnO thin films in the phase and investigates the conditions under which the synergy of ferroelectric and photoactive properties, can be achieved to confirm the potential of this material for applications in the development of next-generation photovoltaic devices. Single-phase -LuMnO was successfully deposited on different substrates, and the thermal stability of the material was confirmed by Micro-Raman spectroscopy analysis from 77 to 850 K, revealing the suitable ferro- to para-electric transition near 760 K. Optical measurements confirm the relatively narrow band gap at 1.
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February 2025
Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria.
Silk fibroin (SF), the primary protein in silkworm silk, has emerged as a promising organic nonlinear optical material due to its unique combination of optical transparency, biocompatibility, and environmental sustainability. In this study, we investigate the nonlinear optical properties of SF thin films using the -scan technique with femtosecond laser pulses (35 fs, 800 nm, 1 kHz). Our results reveal a strong self-defocusing effect (negative nonlinear refractive index) and significant multiphoton absorption, demonstrating SF's tunable nonlinear response.
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