A5065916202- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Superconductivity in MgB2 and Alloys
- Topological Materials and Phenomena
- ZnO doping and properties
- Iron-based superconductors research
- Magnetic properties of thin films
- Transition Metal Oxide Nanomaterials
- Rare-earth and actinide compounds
- Multiferroics and related materials
- Semiconductor materials and devices
- Quantum and electron transport phenomena
- Gas Sensing Nanomaterials and Sensors
- Advancements in Solid Oxide Fuel Cells
- Catalytic Processes in Materials Science
- Magnesium Alloys: Properties and Applications
- Magnetic Properties of Alloys
- Graphene research and applications
- Copper Interconnects and Reliability
- Ferroelectric and Piezoelectric Materials
- Microwave Engineering and Waveguides
- Antenna Design and Analysis
- Advanced Antenna and Metasurface Technologies
Istituto Officina dei Materiali
2018-2025
National Research Council
2016-2025
AREA Science Park
2017-2024
University of Salerno
2013-2022
International School of Trieste
2022
Superconducting and other Innovative Materials and Devices Institute
2010-2019
IRCCS San Camillo Hospital
2010
Pennsylvania State University
2005-2009
University of Rome Tor Vergata
2002-2006
Coherent (United States)
2004-2005
Kagome materials have emerged as a setting for emergent electronic phenomena that encompass different aspects of symmetry and topology. It is debated whether the XV$_6$Sn$_6$ kagome family (where X rare earth element), recently discovered bilayer metals, hosts topologically non-trivial ground state resulting from opening spin-orbit coupling gaps. These states would carry finite spin-Berry curvature, topological surface states. Here, we investigate spin structure family. We obtain evidence...
The relation between crystal symmetries, electron correlations, and electronic structure steers the formation of a large array unconventional phases matter, including magneto-electric loop currents chiral magnetism. Detection such hidden orders is major goal in condensed matter physics. However, to date, nonstandard forms magnetism with ordering have been experimentally elusive. Here, we develop theory for symmetry-broken ground states propose methodology based on circularly polarized...
The nature of the metal insulator transition in thin films and superlattices LaNiO3 with only few unit cells thickness remains elusive despite tremendous effort. Quantum confinement epitaxial strain have been evoked as mechanisms, although other factors such growth-induced disorder, cation non-stoichiometry, oxygen vacancies, substrate-film interface quality may also affect observable properties ultrathin films. Here we report results obtained for near-ideal different thicknesses...
Abstract Long-range electronic ordering descending from a metallic parent state constitutes rich playground to study the interplay of structural and degrees freedom. In this framework, kagome metals are in most interesting regime where both phonon electronically mediated couplings significant. Several these systems undergo charge density wave transition. However, date, origin main driving force behind order is elusive. Here, we use metal ScV 6 Sn as platform investigate problem, since it...
In this paper, we illustrate an approach to discriminate between epitaxial strain and other factors responsible for the decrease of metal–insulator transition temperature (TP) in thin La0.7Sr0.3MnO3 films grown by pulsed laser deposition. Using approach, have estimated effect biaxial on TP. Ultrathin films, independent strain, do not show any over full range. This finding confirms existence interface dead layer. The strain-independent TP, relative its bulk value, observed a much wider...
The role of trivalent rare-earth dopants on the cerium oxidation state has been systematically studied by in situ photoemission spectroscopy with synchrotron radiation for 10 mol % doped epitaxial ceria films. It was found that dopant rare-earths smaller ionic radius foster formation Ce3+ releasing stress strength induced cation substitution. With a decrease from La3+ to Yb3+, out-of-plane axis parameter crystal lattice decreases without introducing macroscopic defects. high quality our...
We report on epitaxial growth of Bi2Se3 topological insulator thin films by Pulsed Laser Deposition (PLD). X-ray diffraction investigation confirms that with a single (001)-orientation can be obtained several substrates in narrow (i.e., 20 °C) range deposition temperatures and at high pressure 0.1 mbar). However, only grown (001)-Al2O3 show an almost-unique in-plane orientation. In-situ spin-resolved angular resolved photoemission spectroscopy experiments, performed the NFFA-APE facility...
Long-range electronic order descending from a metallic parent state constitutes rich playground to study the intricate interplay of structural and degrees freedom. With dispersive correlation features as multifold topological Dirac-like itinerant states, van-Hove singularities, correlated flat bands, magnetic transitions at low temperature, kagome metals are located in most interesting regime where both phonon electronically mediated couplings significant. Several these systems undergo...
Electrostriction is the upsurge of strain under an electric field in any dielectric material. Oxygen-defective metal oxides, such as acceptor-doped ceria, exhibit high electrostriction 10-17 m2V-2 values, which can be further enhanced via interface engineering at nanoscale. This effect ceria "non-classical" it arises from intricate relation between defect-induced polarisation and local elastic distortion lattice. Here, we investigate impact mismatch when epitaxial Gd-doped CeO2 thin films...
Spinel-type lithium manganese oxide (LiMn2O4) is considered one of the most promising cathode materials for rechargeable batteries due to its high operating voltage, reduced toxicity, and lower cost compared cobalt-based cathodes. However, stability LiMn2O4 a significant challenge, as it tends degrade over time, with ion segregation leading reduction in battery capacity.
<title>Abstract</title> The study of rare-earth nickelates, such as LaNiO<sub>3</sub> (LNO), is significant due to their complex electronic properties. Ordered oxygen vacancies (OOV) in LaNiO<sub>3 − x</sub> decrease conductivity, converting it from metallic insulating state 'x' approaches 0.5, and semiconducting behavior near x = 0.75. These OOV also influence magnetic properties, causing LNO exhibit anti-ferromagnetic ferromagnetic instead its usual paramagnetic state. Interfacial strain...
The kagome geometry is an example of a frustrated configuration in which rich physics takes place, including the emergence superconductivity and charge density wave (CDW). Among metals, $\mathrm{S}\mathrm{c}{\mathrm{V}}_{\mathrm{6}}\mathrm{S}{\mathrm{n}}_{\mathrm{6}}$ hosts unconventional CDW, with its electronic order showing different periodicity from leading lattice instability. In this material, CDW-softened flat phonon band has second-order collapse at same time that first-order...
Abstract We report on the epitaxial growth of Bi$_{2}$WO$_{6}$ thin films by Pulsed Laser Deposition using a high-power infrared Nd:YAG laser source. X-ray diffraction investigation confirms that single (00$l$)-oriented can be obtained both LSAT and SrTiO$_{3}$ substrates LaNiO$_{3}$ adapting layer. Moreover, reciprocal space maps show coherently grow such with in-plane lattice parameters fully matching those substrates. In-situ x-ray photoemission spectroscopy experiments UHV annealing...
Oxygen-deficient titanium dioxide (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mi>TiO</a:mi><a:mrow><a:mn>2</a:mn><a:mo>−</a:mo><a:mi>x</a:mi></a:mrow></a:msub></a:math>) is a very attractive material for several applications ranging from photocatalysis to resistive switching. Oxygen vacancies turn insulating anatase into polaronic conductor, while creating defect-state band below the ultraviolet semiconducting gap. Here we employ combination of broadband infrared (IR)...
The magnetic and electronic modifications induced at the interfaces in ${({\text{SrMnO}}_{3})}_{n}/{({\text{LaMnO}}_{3})}_{2n}$ superlattices have been investigated by linear circular dichroism $\text{Mn}\text{ }{L}_{2,3}$ x-ray absorption spectra. Together with theoretical calculations, our data demonstrate that charge redistribution across favors in-plane ferromagnetic (FM) order ${e}_{g}({x}^{2}\ensuremath{-}{y}^{2})$ orbital occupation, agreement average strain. Far from interfaces,...
We report on the role of oxygen content alone structural and transport properties La0.65Sr0.35MnO3−δ (LSMO) thin films. Identical films were deposited side-by-side during a single deposition run subsequently post-annealed separately in vacuum to systematically vary content. All remained coherently strained SrTiO3 substrate, with no broadening rocking curve widths after post-anneal. As decreases, LSMO unit cell expands while metal-insulator transition temperature TMI decreases. A linear...
We report on the growth and characterization of ultrathin YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) films MgO (110) substrates, which exhibit superconducting properties at thicknesses down to 3 nm. YBCO nanowires, with 10 nm widths 65 nm, have been also successfully fabricated. The nanowires protected by a Au capping layer show close as-grown films, critical current densities, are only limited vortex dynamics. thick without present hysteretic voltage characteristics, characterized switch drives...
Samaria-doped ceria (SDC) thin films are particularly important for energy and electronic applications such as microsolid oxide fuel cells, electrolyzers, sensors, memristors. In this paper, we report a comparative study investigating ionic conductivity surface reactions well-grown epitaxial SDC varying the samaria doping concentration. With increasing above 20 mol % of samaria, an enhancement in defect association is observed by Raman spectroscopy. The role associated defects on films̀...
Abstract Quantum materials are central for the development of novel functional systems that often based on interface specific phenomena. Fabricating controlled interfaces between quantum requires adopting a flexible growth technique capable to synthesize different within single-run deposition process with high control structure, stoichiometry, and termination. Among various available thin film technologies, pulsed laser (PLD) allows controlling diverse at level single atomic layers. In PLD...
We use resonant inelastic x-ray scattering to probe the propagation of plasmons in electron-doped cuprate superconductor Sr_{0.9}La_{0.1}CuO_{2}. detect a plasmon gap ∼120 meV at two-dimensional Brillouin zone center, indicating that low-energy Sr_{0.9}La_{0.1}CuO_{2} are not strictly acoustic. The dispersion, including gap, is accurately captured by layered t-J-V model calculations. A similar analysis performed on recent data from other cuprates suggests generic and its size related...
The low-temperature $(<60\phantom{\rule{0.3em}{0ex}}\mathrm{K})$ transport properties of as-grown ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ ultrathin films, deposited by the molecular beam epitaxy, have been investigated as a function sample thickness (from $40\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}3.5\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) and in presence an external magnetic field. With decreasing thickness, clear resistivity minimum...
Double-exchange (DE) mechanisms in $R{E}_{1\ensuremath{-}x}A{E}_{x}{\text{MnO}}_{3}$ manganites (where $RE$ is a trivalent rare-earth ion and $AE$ divalent alkali-earth ion) relies on the strong exchange interaction between two ${\text{Mn}}^{3+}$ ${\text{Mn}}^{4+}$ ions through interfiling oxygen $2p$ states. Nevertheless, role of has ever been considered ``silent'' with respect to DE conducting mechanisms. Here we show that new path for mechanism indeed possible by partially replacing...
Oxygen vacancies are known to play a crucial role in tuning the physical properties and technological applications of titanium dioxide TiO2. Over last decades, defects substoichiometric TiO2 have been commonly associated with formation TinO2n-x Magnéli phases, which extended planar originating from crystallographic shear planes. By combining advanced transmission electron microscopy techniques, energy-loss spectroscopy atomistic simulations, we reach new understanding oxygen vacancy induced...
Two-dimensional (2D) metallic states induced by oxygen vacancies (${V}_{O}\mathrm{s}$) at oxide surfaces and interfaces provide opportunities for the development of advanced applications, but ability to control behavior these is still limited. We used angle resolved photoelectron spectroscopy combined with density-functional theory (DFT) study reactivity ${V}_{O}$-induced (001) surface anatase ${\mathrm{TiO}}_{2}$, where both 2D deeper lying in-gap (IGs) are observed. The IG exhibit...