A5041481454- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Semiconductor materials and devices
- Ferroelectric and Negative Capacitance Devices
- MXene and MAX Phase Materials
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- ZnO doping and properties
- Advanced Memory and Neural Computing
- Magnetic Properties and Synthesis of Ferrites
- Acoustic Wave Resonator Technologies
- Catalytic Processes in Materials Science
- Laser-induced spectroscopy and plasma
- Dielectric properties of ceramics
- Magneto-Optical Properties and Applications
- Spanish Literature and Culture Studies
- Theoretical and Computational Physics
- Laser Material Processing Techniques
- Rare-earth and actinide compounds
- Force Microscopy Techniques and Applications
- Advanced Surface Polishing Techniques
- Diamond and Carbon-based Materials Research
Institut de Ciència de Materials de Barcelona
2016-2025
Universitat Autònoma de Barcelona
1999-2023
Centre National de la Recherche Scientifique
2009-2022
GREYC
2022
Normandie Université
2022
École Nationale Supérieure d'Ingénieurs de Caen
2022
Université de Caen Normandie
2022
Centre de Recerca Matemàtica
2014-2019
Consejo Superior de Investigaciones Científicas
1999-2019
Institute of Applied Science and Intelligent Systems
2019
The magnetic exchange between epitaxial thin films of the multiferroic (antiferromagnetic and ferroelectric) hexagonal YMnO3 oxide a soft ferromagnetic (FM) layer is used to couple response FM state antiferromagnetic one. We will show that biasing ferroelectric by an electric field allows control bias subsequently magnetotransport properties layer. This finding may contribute paving way towards new generation electric-field controlled spintronic devices.
Giant photovoltaic effect due to bulk observed in multiferroic BiFeO3 thin films has triggered a renewed interest on photoferroelectric materials for applications. Tremendous advance been done improve power conversion efficiency (up up 8.1%) photoferroelectrics via absorption increase using narrow bandgap ferroelectrics. Other strategies, as it is the more efficient use of ferroelectric internal electric field, are ongoing. Moreover, by-product, several progress have also achieved...
The critical impact of epitaxial stress on the stabilization ferroelectric orthorhombic phase hafnia is proved. Epitaxial bilayers Hf0.5Zr0.5O2 (HZO) and La0.67Sr0.33MnO3 (LSMO) electrodes were grown a set single crystalline oxide (001)-oriented (cubic or pseudocubic setting) substrates with lattice parameter in 3.71–4.21 Å range. strain LSMO electrode, determined by mismatch substrate, HZO. On tensilely strained electrodes, most HZO film orthorhombic, whereas monoclinic favored when relaxed...
Ferroelectric hafnium and zirconium oxides have undergone rapid scientific development over the last decade, pushing them to forefront of ultralow-power electronic systems. Maximizing potential application in memory devices or supercapacitors these materials requires a combined effort by community address technical limitations, which still hinder their application. Besides favorable intrinsic material properties, HfO2–ZrO2 face challenges regarding endurance, retention, wake-up effect, high...
In spite of being highly relevant for the development a new generation information storage devices, not many single-phase materials displaying magnetic and ferroelectric orders above room temperature are known. Moreover, these uncommon typically display insignificant values remanent moment in one ferroic or complex multicomponent oxides which will be very challenging to integrate devices. Here we report on strategy stabilize metastable epsilon-Fe2O3 thin film form, show that besides its...
Abstract The discovery of two-dimensional electron gases (2DEGs) at oxide interfaces—involving electrons in narrow d -bands—has broken new ground, enabling the access to correlated states that are unreachable conventional semiconductors based on s - and p electrons. There is a growing consensus emerging properties these novel quantum wells—such as 2D superconductivity magnetism—are intimately connected specific orbital symmetries 2DEG sub-band structure. Here we show crystal orientation...
We demonstrate that the magnetization of a ferromagnet in contact with an antiferromagnetic multiferroic (LuMnO(3)) can be speedily reversed by electric-field pulsing, and sign magnetic exchange bias switch recover isothermally. As LuMnO(3) is not ferroelastic, our data conclusively show this switching mediated strain effects but unique driven decoupling ferroelectric domain walls. Their distinct dynamics are essential for observed switching.
In recent years, striking discoveries have revealed that two-dimensional electron liquids (2DEL) confined at the interface between oxide band-insulators can be engineered to display a high mobility transport. The recognition only few interfaces appear suit hosting 2DEL is intriguing and challenges understanding of these emerging properties not existing in bulk. Indeed, neutral TiO(2) surface (001)SrTiO(3) has been shown sustain 2DEL. We show this restriction surpassed: (110) (111) surfaces...
Several experimental methods to measure ferroelectric hysteresis loops and extract polarization values are compared for thin films with significant losses different magnitudes of polarization. The analysis allows the determination most appropriate frequency range technique reliable remanent in materials low high leakage. Examples include multiferroic YMnO3 Bi0.9La0.1NiMnO6 films.
About ten years after ferroelectricity was first reported in doped HfO2 polycrystalline films, there is tremendous interest this material and ferroelectric oxides are once again the spotlight of memories industry. Great efforts being made to understand control properties. Epitaxial which have fewer defects a more controlled microstructure than can be very useful for purpose. films been much less investigated, but report 2015 significant progress has achieved. This review summarizes discusses...
Ferroelectric orthorhombic Hf0.5Zr0.5O2 thin films have been stabilized epitaxially on La2/3Sr1/3MnO3/SrTiO3(001) by pulsed laser deposition. The epitaxial films, (111)-oriented and with a very flat surface, show robust ferroelectric properties at room temperature. They present remnant polarization around 20 μC/cm2 without the need of wake-up process, large coercive electric field 3 MV/cm, an extremely long retention extending well beyond 10 years, endurance up to about 108 cycles. Such...
Epitaxial ferroelectric HfO2 films are the most suitable to investigate intrinsic properties of material and for prototyping emerging devices. Ferroelectric Hf0.5Zr0.5O2(111) have been epitaxially stabilized on La2/3Sr1/3MnO3(001) electrodes. This epitaxy, considering symmetry dissimilarity huge lattice mismatch, is not compatible with conventional mechanisms epitaxy. To gain insight into epitaxy mechanism, scanning transmission electron microscopy characterization interface was performed,...
SrTiO3 templates have been used to integrate epitaxial bilayers of ferroelectric Hf0.5Zr0.5O2 and La2/3Sr1/3MnO3 bottom electrode on Si(001). The films show enhanced properties in comparison equivalent SrTiO3(001) single crystalline substrates. films, thinner than 10 nm, very high remnant polarization 34 uC/cm2. capacitors at operating voltage 4 V present long retention time well beyond years endurance against fatigue up 109 cycles. robust displayed by the Si(001) using paves way for...
We show that atomically flat single SrO-terminated SrTiO3(001) substrates can be obtained through simple high-temperature treatment. Amplitude-modulation atomic force microscopy with phase-lag analysis and x-ray photoelectron spectroscopy, have been used to demonstrate the ratio between two chemical terminations tailored by choosing annealing time. Moreover, progressive SrO surface enrichment (up 100%) is accompanied a self-assembly process which results in spatial separation at nanoscale of...
We demonstrate that epitaxial strain engineering is an efficient method to manipulate the ferromagnetic and ferroelectric properties in BiFeO3−CoFe2O4 columnar nanocomposites. On one hand, magnetic anisotropy of CoFe2O4 totally tunable from parallel perpendicular controlling with proper combinations substrate phase. other selection used allows growth rhombohedral bulk phase BiFeO3 or metastable nearly tetragonal one, which implies a rotation polar axis [111] close [001] direction....
We report magnetoresistance measurements on thin Pt bars grown epitaxial (001) and (111) CoFe2O4 (CFO) ferrimagnetic insulating films. The results can be described in terms of the recently discovered spin Hall (SMR). magnitude SMR depends interface preparation conditions, being optimal when Pt/CFO samples are prepared situ, a single process. spin-mixing conductance, key parameter governing other relevant spin-dependent phenomena, such as pumping or Seebeck effect, is found to different...
Abstract The response of epitaxial CoFe 2 O 4 thin films to biaxial compressive stress imposed by MgAl and SrTiO 3 single crystalline substrates is studied using X‐ray diffraction Raman spectroscopy. It found that the Poisson ratio ν signals a non‐auxetic behavior depends on substrate used. modes show an increase in frequency when increasing strain reducing film thickness; this due shrinking unit cell volume. Such qualitative agreement with recent ab initio calculations, although measured...
Doping ferroelectric Hf0.5Zr0.5O2 with La is a promising route to improve endurance. However, the beneficial effect of on endurance polycrystalline films may be accompanied by degradation retention. We have investigated - retention dilemma in La-doped epitaxial films. Compared undoped films, large values polarization are obtained wider thickness range, whereas coercive fields similar, and leakage current substantially reduced. show more fatigue but there not significant wake-up...
Epitaxial ferroelectric Hf0.5Zr0.5O2 films have been successfully integrated in a capacitor heterostructure on Si(001). The orthorhombic phase, [111] out-of-plane oriented, is stabilized the films. present high remnant polarization Pr close to 20 μC/cm2, rivaling with equivalent epitaxial single crystalline oxide substrates. Retention time longer than 10 years for writing field of around 5 MV/cm, and capacitors show endurance up 109 cycles voltage 4 MV/cm. It found that formation phase...
In the quest for energy efficient and fast memory elements, optically controlled ferroelectric memories are promising candidates. Here, we show that, by taking advantage of imprint electric field existing in nanometric BaTiO3 films their photovoltaic response at visible light, polarization suitably written domains can be reversed under illumination. We exploit this effect to trigger measure associate change resistance tunnel devices. that engineering device structure inserting an auxiliary...
In the quest for reliable and power-efficient memristive devices, ferroelectric tunnel junctions are being investigated as potential candidates. CMOS-compatible hafnium oxides at forefront. However, in epitaxial devices with thicknesses around ${\approx}$ 4 - 6 nm, relatively high energy barrier produces a large resistance that challenges their implementation. Here, we show electroresistive switching can be observed ultrathin 2 nm Hf$_{0.5}$Zr$_{0.5}$O$_2$ (HZO) area capacitors (${\approx}...
Epitaxial thin films of HfO2 doped with La have been grown on SrTiO3(001) and Si(001), the impact concentration stabilization ferroelectric phase has determined. Films 2-5 at. % doping present least amount paraelectric monoclinic cubic phases exhibit highest polarization, having a remanent polarization above 20 μC/cm2. The dopant results in an important effect coercive field, which is reduced increasing content. Combined high retention, endurance at 1010 cycles obtained 5 La-doped films.
The metastable orthorhombic phase of Hf0.5Zr0.5O2 (HZO) can be stabilized in thin films on La0.67Sr0.33MnO3 (LSMO) buffered (001)-oriented SrTiO3 (STO) by intriguing epitaxy that results (111)-HZO oriented growth and robust ferroelectric properties. Here, we show the also epitaxially LSMO/STO(110), presenting same out-of-plane (111) orientation but a different distribution in-plane crystalline domains. remanent polarization HZO with thickness less than 7 nm LSMO/STO(110) is 33 μC cm-3, which...