Stefania Florina Rus

Institutul National De Cercetare – Dezvoltare Pentru Electrochimie Si Materie Condensata | INCDEMC · Renewable Energies Laboratory – Photovoltaics,

The optical band gap of the prototypical semiconducting oxide SnO2 is shown to be continuously controlled through single axis lattice expansion of nanometric films induced by low-energy helium implantation. While traditional epitaxy induced strain results in Poisson driven multi-directional lattice changes shown to only allow discrete increases in...

In the context of water electrolysis being highlighted as a promising technology for the large-scale sustainable production of hydrogen, the water-splitting electrocatalytic properties of an asymmetrically functionalized A3B zinc metalated porphyrin, namely, Zn(II) 5-(4-pyridyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin, were evaluated in a wide pH...

Carbon aerogels represent a distinctive category of high surface area materials derived from sol-gel chemistry. Functionalizing these aerogels has led to the development of composite aerogels with the potential for a wider range of applications. In this study, the technique of lyophilization was employed to fabricate aerogel composites consisting o...

Type I collagen, prevalent in the extracellular matrix, is biocompatible and crucial for tissue engineering and wound healing, including angiogenesis and vascular maturation/stabilization as required processes of newly formed tissue constructs or regeneration. Sometimes, improper vascularization causes unexpected outcomes. Vascularization failure m...

Tellurium oxides of the ATeO3 form typically do not crystallize in perovskite structures. Here, we show that perovskite-like ATeO3 (A = Ca, Sr, Ba) thin films can be grown on perovskite single-crystal substrates via epitaxial stabilization. These films are stable with high optical bandgaps, low dielectric losses, and a high electric breakdown stren...

Bismuth-based oxides with chemical formula ABiO 3 , where A = Ca, Zn, Mg, have been recently synthesized and suggested to host ferroelectricity. As these materials possess favorable optical properties, the presence of ferroelectricity with large polarization would further enhance the possible applications, for example, in photovoltaics by improving...

This study focuses on the development of a Ca-Bi-O system (CBO) with efficiency in the degradation of Rhodamine B, which is extremely toxic to many organisms and can have long-term negative consequences if not safely removed from the water. The conventional precipitation method was used to create a stable phase of Ca2Bi2O5 with a stoichiometric 1:1...

We demonstrate the heteroepitaxial growth of phase-pure bronze-phase TiO2 films using pulsed laser deposition on MgAl2O4 single-crystal substrates. While the growth on cubic substrates with smaller lattice parameters favors the stabilization of an out-of-plane-oriented anatase phase, and the use of substrates with larger lattice parameters leads to...

This work is licensed under Creative Commons Attribution 4.0 License MCMS.MS.ID.000596. Abstract The thermal and optical properties of commercial glass foam covered with a functional coating designed for exterior and environmental applications were investigated. The coating was prepared using WO 3 a photocatalytic material-as a pigment and acrylic...

Hydrothermally obtained α-MnO2 nanowire characterizations confirm the tetragonal crystalline structure that is several micrometers long and 20–30 nm in diameter with narrow distributions in their dimensions. The absorption calculated from diffuse reflectance of α-MnO2 occurred in the visible region ranging from 400 to 550 nm. The calculated band ga...

The coating of orthopedic and dental implants with hydroxyapatite (HA) is recognized as a method to increase their integration ability. A new metal coating method, comprising simultaneous precipitation and electrodeposition, is presented. Two studies are described: the first is related to the influence of time/temperature increase on the morpho-str...

Commercial glass foam was covered with 1–4 layers of coating containing titanium dioxide (TiO2) to study thermal efficiency and changes in the reflection and emissivity spectrum in correlation with the number of layers. The morpho-structural and optical properties of the coated foam glass were studied by X-ray diffraction (XRD), Fourier transform-i...

An efficient fast hydrothermal method was used to synthesize Co1-xPdxFe2O4 (x = 0, 0.05, 0.1 and 0.5) nanocrystalline powders, where Co²⁺ was substituted with Pd²⁺ ions. The materials crystallize within the spinel structure (Fd-3m) with crystallites sizes varying between 5.6 and 17.6 nm. The particles present a cubic shape for x = 0 and x = 0.1 sam...

Hybrid nanomaterials can have superior properties in comparison with individual components, sometimes greatly improving their optoelectronic activity. For this reason, modified carbon electrodes were obtained using a hybrid material composed of 5,10,15,20-tetra(4-tolyl)porphyrinato manganese (III) chloride (MnTTP) embedded in a silica matrix. The l...

In this paper, a photocatalytic evaluation was carried out for several synthetized samples of glass foam coated with different amounts of TiO2 and WO3, respectively in order to investigate their capacity to remove Rhodamine B (RhB) from aqueous solution, under simulated solar irradiation. As the organic dyes are considered a major source of polluti...

The effect of germanium trapezoidal profile shape on the direct current (DC) current gain (βF), cut-off frequency (fT) and maximum oscillation frequency (fMAX) of silicon-germanium (SiGe) hetero-junction bipolar transistors (HBTs) has been investigated. The energy balance (EB), hydrodynamic (HD) and drift-diffusion (DD) physical transport models in...

The study herein reports the synthesis by hydrothermal method at 200 °C for 12 h, followed by heat treatment at 600 °C for 6 h of NaNbO3 materials, undoped and Zr-doped at different concentrations (1, 2 and 3%). The influence of Zr doping in NaNbO3 compounds on the morpho-structural and optical properties as well as their dependence on dopant conce...

The impact of single-axis lattice expansion on the optical response of BiFeO3 films is examined. Low-energy He implantation is used to tailor morphotropic phases of BiFeO3 films and study changes in their optical spectra with continuously increasing lattice expansion. He ion implantation of epitaxial rhombohedral (R)- and tetragonal (T)-like BiFeO3...

The final published print version inadvertently did not include the appropriate funding acknowledgment for RR and SFR. The complete acknowledgement is as follows: Acknowledgments This work was supported by the U.S. Department of Energy (DOE), Office of Science, Early Career Research Program, and Office of Science, Basic Energy Sciences, Materials...

The coupling between a material’s lattice and its underlying spin state links structural deformation to magnetic properties; however, traditional strain engineering does not allow the continuous, post-synthesis control of lattice symmetry needed to fully utilize this fundamental coupling in device design. Uniaxial lattice expansion induced by post-...

In this work, we demonstrate that the optical bandgap of WO3films can be continuously controlled through uniaxial strain induced by low-energy helium implantation. The insertion of He into epitaxially grown and coherently strained WO3films can be used to induce single axis out-of-plane lattice expansion of up to 2%. Ellipsometric spectroscopy revea...

The capability to control the structures and physical and chemical properties, including chemical reactions at surfaces or interfaces of novel material systems with low-dimensional structures, is a major goal in functional materials research. Our previous results proved that “strain doping” is an efficient way to tailor thin film properties. We hav...

With the ever present-to-future need of renewable energy the main features of photo-electrochemistry processes are reviewed and described from the perspective of devices phenomenology serving to sustainable design of photovoltaics, while providing the quantum insight in terms of data observability and interpretation. At the same time, the photovolt...

With the ever present-to-future need of renewable energy the main features of photo-electrochemistry processes are reviewed and described from the perspective of devices phenomenology serving to sustainable design of photovoltaics, while providing the quantum insight in terms of data observability and interpretation. At the same time, the photovolt...

The main purpose of this research was to obtain manganese porphyrin/gold nanoparticle-modified glassy carbon electrodes and to use them for the detection of H2O2. Two sets of modified electrodes were prepared by drop-cast deposition of 5,10,15,20-tetra(4-methyl-phenyl)porphyrinato manganese(III) chloride alone and of the same Mn-porphyrin and gold-...

Thickness dependent strain relaxation effects are utilized to study the impact of crystal anisotropy on the optical band gap of epitaxial SnO2 films grown by pulsed laser deposition on (0001)-oriented sapphire substrates. An X-ray diffraction analysis reveals that all films are under tensile biaxial in-plane strain and that strain relaxation occurs...

Nanocrystalline ferrites; CoFe2O4 (CFO) and CoFe1.9Zr0.1O4 (CFZO) have been synthesized through chemical coprecipitation method. The role played by the zirconium ions in improving the magnetic and structural properties is analyzed. X-ray diffraction revealed a single-phase cubic spinel structure for both materials, where the crystallite size increa...

Sodium niobate (NaNbO3) fine powders were synthesized by hydrothermal method using ammonium niobate (V) oxalate hydrate (C4H4NNbO9 x H2O), sodium hydroxide (NaOH) and sodium citrate hydrate (C6H9Na3O9) as precursors. The samples were characterized by X-Ray diffraction (XRD), scanning electron microscopy (SEM), AFM (Atomic Force Microscopy), UV-VIS...

The aim of this study is the enhancement of the electrical properties of thin films obtained from silver nanowires (AgNWs) deposited on a flexible polyethylene terephthalate (PET) support. First, AgNWs were obtained by the “polyol” liquid phase synthesis method in the presence of chloride ions. After purification, the AgNWs were successively deposi...

Abstract We have grown epitaxial Sn substituted cobalt ferrite thin films of various thicknesses on piezoelectric Pb(Mg1/3Nb2/(3))(0.72)Ti0.28O3 substrates and investigated the strain-induced changes of magnetic properties. All films described in this work have been deposited by pulsed laser deposition (PLD) from stoichiometric target of Co0.9Sn0.1...

We report on the structural and magnetic properties of CoFe1.9Zr0.1O4 films under epitaxial strain. The films are grown with high structural quality on MgO, SrTiO3, and piezoelectric Pb(Mg1∕3Nb2∕3)0.72Ti0.28O3 substrates by pulsed laser deposition. The substrate-induced strain is found effective to alter the magnetic anisotropy of the films. Revers...

Cobalt ferrite substituted with indium, CoFe2-xInxO4 (x = 0.05, 0.1 and 0.5 mol), was obtained by the original fast hydrothermal method and the effects of the substitution on morphology and magnetic and optical properties of cobalt ferrite were investigated. The obtained nanoparticle samples with different concentrations of the substitute (Fe3+ was...

Epitaxial CoFe2O4 (CFO) films of varying thickness were grown on piezoelectric Pb(Mg1∕3Nb2∕3)0.72Ti0.28O3 substrates. The magnetic anisotropy of the CFO films is controlled by the piezoelectric in-plane strain imposed by the substrate constraint during application of an electric field. We find that the strain-induced change of the remanent magnetiz...

Copper ferrite nanoparticles were synthesized by hydrothermal ultrasonically assisted method using iron nitrate and copper nitrate as precursors in aqueous alkaline solution. Mixing process was performed using an immersed sonotrode in synthesis environment. Ultrasonic treatment was performed at 100 W/40 kHz during the hydrothermal synthesis at 200°...