Author Archive

Switchable photovoltaic response in hexagonal LuMnO3 single crystals

Yunwei Sheng, Ignasi Fina, Marin Gospodinov, and Josep Fontcuberta

Appl. Phys. Lett. 118, 232902 (2021);  DOI: doi.org/10.1063/5.0053379

 

Hexagonal manganites, such as h-LuMnO3, are ferroelectric with its polar axis along the hexagonal axis and have a narrow electronic bandgap (≈1.5 eV). Using Pt electrodes, h-LuMnO3 single crystals display a strong rectification, characteristic of a Schottky diode, and a large photoresponse. It is found that the short circuit photocurrent density Jsc along the polar axis is modulated (up to 25%) by the direction of the ferroelectric polarization P, leading to a short circuit photocurrent loop that mimics the ferroelectric polarization. However, a non-switchable Jsc persists. Diffusion photocurrent is shown to dominate current-in-plane measurements and contributes to the non-switchable Jsc. This observation illustrates the dramatic role of the large optical absorption in hexagonal manganites. The accompanying optical dichroism might challenge disentangling a genuine bulk photovoltaic response in h-LuMnO3 single crystals, contributing to the non-switchable Jsc. Epitaxial thin films may offer a suitable alternative.
 
 

Orbital occupancy and hybridization in strained SrVO3 epitaxial films

Mathieu Mirjolet , Hari Babu Vasili, Adrian Valadkhani, José Santiso , Vladislav Borisov, Pierluigi Gargiani, Manuel Valvidares, Roser Valentí , and Josep Fontcuberta

Phys Rev. Materials 5, 095002 (2021),  DOI:10.1103/PhysRevMaterials.5.09500212K

Strain is a knob that allows tuning the electronic bandwidth or the electronic distribution within the atomic orbitals is solids, to promote dramatic changes of their properties or even to induce emerging ones, such as metal-insulator transitions, ferroelectricity, ferromagnetism or superconductivity, to mention a few.

SrVO3 is an excellent metal of the highest interest in technology. Epitaxial strain affects the electronic conductivity supposedly by changing the electronic distribution within the 3d(t2g) orbitals and their corresponding bandwidth.

Here, we show that the role of strain is more involved. It turns out that the V-O hybridization is substantially modified by unbalancing the 3d(t2g)-2p molecular orbital mixtures. It follows that not only the orbital hierarchy of the (xy, xz and yz) orbitals of the t2g manifold is modified but also the amount of electrons at 3d(t2g) orbitals of the metal ion also change with strain. In other words, a rigid band picture does not hold even in this seemingly simple metallic oxide

Alejandro Sánchez Miñarro

Hello all! My name is Alex and after finish my Bachelor degree on Physics at Universitat de Barcelona and my Master degree on Photonics at Universitat Politècnica de Catalunya I’ve just joined to MULFOX group to start my PhD about photonic metasurfaces with topological properties under the supervision of Dr. Gervasi Herranz. I’m glad to be here and eager to start this new stage!

 

Gyanendra Singh

Hello everyone! My name is Gyanendra Singh, from India. I have joined ICMAB as a postdoctoral researcher within the Beatriu de Pinós program (BP 2019). I will be investigating the possibilities of spintronics devices in two-dimensional layers and interfaces under Gervasi Herranz’s guidance. I look forward to interacting with you all
 

Thickness effect on ferroelectric properties of La-doped HfO2 epitaxial films down to 4.5 nm

Tingfeng Song, Romain Bachelet, Guillaume Saint-Girons, Nico Dix, Ignasi Fina and Florencio Sanchez

J. Mater. Chem. C, 2021,  DOI: doi.org/10.1039/D1TC02512K

Stabilization of the orthorhombic phase of HfO2 with La allows very high polarization and endurance. However, these properties have not been confirmed yet in films having thickness of less than 10 nm. We have grown (111)-oriented La (2 at%) doped epitaxial HfO2 films on SrTiO3(001) and Si(001) substrates, and we report on the thickness dependence of their ferroelectric properties.
Films of less than 7 nm have a high remanent polarization of about 30 µC cm-2, show slight wake-up, endurance of at least 1010 cycles and retention of more than 10 years, both latest properties measured at the same poling voltage. La-doped HfO2 films even as thin as 4.5 nm also show robust ferroelectric properties.
 

Congratulations Dr. Mathieu Mirjolet!

Doctor Mathieu Mirjolet from the Laboratory of Multifunctional Thin Films and Complex Structures (MULFOX) group at ICMAB, defended his PhD thesis titled “Transparent Conducting Oxides Based on Early Transition Metals: From Electrical and Optical Properties of Epitaxial Thin Films, to Integration in All-Oxide Photoabsorbing Heterostructures.” on Friday, 23 July 2021 in an online session. Congrats!

 

Electron–Phonon Coupling and Electron–Phonon Scattering in SrVO3

M. Mirjolet, F. Rivadulla, P. Marsik, V. Borisov, R. Valentí, J. Fontcuberta,

J. Adv. Sci. 2021, 2004207. https://doi.org/;      DOI:doi.org/10.1002/advs.202004207

 

 
  • The nature of electron-electron and electron-lattice interactions in metallic oxides is revised. The common wisdom is that the strong correlations among electrons determine their properties.
  • Here we argue that the unavoidable coupling between free electrons and the lattice in ionic materials leads to the formation of polarons. These are carriers dressed by a lattice distortion that travel with them and largely determine the transport and some optical properties.
  • Moreover, we argue that in early transition metal oxides, the Fermi surface has a cylindrical shape that limits the phonons available for scattering.
  • Taking SrVO3as illustrative example of a Fermi liquids, we demonstrate that both mechanisms can contribute to the ubiquitously observed quasi-T2temperature dependence of the electrical resistivity in many metallic oxides.
  • A new twist on the physics of Fermi liquids in ionic lattices.

Optical Plasmon Excitations in Transparent Conducting SrNbO3 and SrVO3 Thin Films

Mathieu Mirjolet, Mikko Kataja, Tommi K. Hakala, Philipp Komissinskiy, Lambert Alff, Gervasi Herranz, Josep Fontcuberta,

Adv. Opt. Materials First published: 14 June 2021;      DOI:doi.org/10.1002/adom.202100520

From catalysis and flat panel displays to photovoltaics, transparent and conducting transition metal oxides are gaining momentum toward more sustainable and cost-efficient applications.

Here it is shown that, without using phase-matching arrangements, bulk plasmons can be excited in continuous epitaxial films of metallic SrVO3 and SrNbO3, with plasma absorption edges at visible range, and tuned mainly by electron correlations and phonon dressing.

Films can be made reflective or transparent at whish.

Stabilization of the Ferroelectric Phase in Epitaxial Hf1–xZrxO2 Enabling Coexistence of Ferroelectric and Enhanced Piezoelectric Properties

Tingfeng Song, Huan Tan, Nico Dix, Rahma Moalla, Jike Lyu, Guillaume Saint-Girons, Romain Bachelet, Florencio Sánchez, and Ignasi Fina

ACS Appl. Electron. Mater. 2021, 3, 5, 2106–2113 (2021);      DOI:doi.org/10.1021/acsaelm.1c00122

Systematic studies on polycrystalline Hf1–xZrxO2 films with varying Zr contents show that HfO2 films are paraelectric (monoclinic). If the Zr content is increased, films become ferroelectric (orthorhombic) and then antiferroelectric (tetragonal). HfO2 shows very good insulating properties and it is used in metal-oxide-semiconductor field-effect devices, while ZrO2 shows good piezoelectric properties, but it is antiferroelectric. In between, Hf0.5Zr0.5O2 shows good ferroelectric properties at the expense of poorer insulating and piezoelectric properties than HfO2 and ZrO2, respectively.
Here, we explore the ferroelectric, insulating, and piezoelectric properties of a series of epitaxial films of Hf1–xZrxO2 with different compositions. We show that epitaxial growth permits the stabilization of the ferroelectric phase in a whole range of Zr content (from x = 0 to x = 1). In epitaxial ZrO2 films, ferroelectricity coexists with better piezoelectric and insulating properties than Hf0.5Zr0.5O2, and in HfO2 epitaxial films, ferroelectricity coexists with better insulating properties than Hf0.5Zr0.5O2. For the case of ZrO2 films, large electroresistance is also observed. In both cases, the ferroelectric endurance is poorer than that for Hf0.5Zr0.5O2.

2021

“Light-Matter Interactions in New Materials and Meta-Architectures”

J. Fontcuberta

META 2021-The 11th International Conference on Metamaterials, Photonic Crystals and Plasmonics

Warsaw (P0land), 20 – 23 July 2021

 

“Spin currents. A probe of interfacial magnetism”

J. Fontcuberta

In-operando adjustable orbital polarization in nickelate perovskites

Moena (Italy), 13 – 16 June 2021

Saúl Estandía defens his PhD Thesis

Nanoscale Study of Epitaxial Ferroelectric Hf0.5Zr0.5O2 Thin Films and BaTiO3/SrTiO3 Superlattices

Date: Friday, 28 May 2021
Time: 11 am

Abstract: This thesis focuses on the characterization of ferroelectric Hf0.5Zr0.5Othin films and BaTiO3/SrTiOsuperlattices by combining scanning transmission electron microscopy, which allows to image the structure and chemistry locally with atomic resolution, with ferroelectric and structure measurements as x-ray diffraction. The first block revealed the ferroelectric dipole configurations in ferroelectric/paraelectric BaTiO3/SrTiO3 superlattices of different periods. A distinct configuration was found in the longest period BaTiO3/SrTiO3 superlattice (10 unit cell-BaTiO3/10 unit cell-SrTiO3), where unforeseen rotations of the polarization were directly imaged. The second block studied the stabilization of ferroelectric Hf0.5Zr0.5Oon perovskite substrates. Since the discovery of ferroelectricity in HfO2-based materials in 2011 these materials have attracted much attention, given their CMOS compatibility and robust nanoscale ferroelectricity, which bears profound advantages for applications. The strong effects of the bottom electrode and the epitaxial stress on the ferroelectricity of Hf0.5Zr0.5Othin films were studied in detail. 

Supervisors:

  • Florencio Sánchez, MULFOX group, ICMAB-CSIC
  • Jaume Gázquez, MULFOX group, ICMAB-CSIC

 

Critical Effect of Bottom Electrode on Ferroelectricity of Epitaxial Hf0.5Zr0.5O2 Thin Films

Saúl Estandía, Jaume Gazquez, Maria Varela, N. Dix, Mengdi Qian, Raul Solanas, Ignasi Fina and Florencio Sanchez

J. Mater. Chem. C, 9, 3486 – 3492 (2021);      DOI:doi.org/10.1039/D0TC05853J

Epitaxial orthorhombic Hf0.5Zr0.5O2 (HZO) films on La0.67Sr0.33MnO3 (LSMO) electrodes show robust ferroelectricity, with high polarization, endurance and retention. However, no similar results have been achieved using other perovskite electrodes so far. Here, LSMO and other perovskite electrodes are compared.
A Small amount of orthorhombic phase and low polarization is found in HZO films grown on La-doped BaSnO3 and Nb-doped SrTiO3, while null amounts of orthorhombic phase and polarization are detected in films on LaNiO3 and SrRuO3.The critical effect of the electrode on the stabilized phases is not consequence of differences in the electrode lattice parameter. The interface is critical, and engineering the HZO bottom interface on just a few monolayers of LSMO permits the stabilization of the orthorhombic phase. Furthermore, while the specific divalent ion (Sr or Ca) in the manganite is not relevant, reducing the La content causes a severe reduction of the amount of orthorhombic phase and the ferroelectric polarization in the HZO film.

Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices

Ignasi Fina* and Florencio Sánchez*

ACS Appl. Electron. Mater. 2021, 3, 4, 1530-1549;      DOI:doi.org/10.1021/acsaelm.1c00110

About ten years after ferroelectricity was first reported in doped HfO2 polycrystalline films, there is tremendous interest in this material and ferroelectric oxides are once again in the spotlight of the memories industry. Great efforts are being made to understand and control ferroelectric properties. Epitaxial films, which have fewer defects and a more controlled microstructure than polycrystalline films, can be very useful for this purpose. Epitaxial films of ferroelectric HfO2 have been much less investigated, but after the first report in 2015 significant progress has been achieved.
This review summarizes and discusses the main advances on epitaxial HfO2, considering growth, study of structural and ferroelectric properties, identification of the ferroelectric phase, and fabrication of devices. We hope this review will help researchers investigating epitaxial HfO2. It can also help extend the interest of the ferroelectric HfO2 community, now basically focused on polycrystalline samples, to epitaxial films.
 

Milena Cervo Sulzbach defens his PhD Thesis

Resistive Switching in Hf0.5Zr0.5O2 ferroelectric tunnel junctionecs

Date: Wednesday, 26 May 2021
Time: 3 pm

Abstract: HfO2-based oxides have been explored as ReRAM elements due to their resistance change caused by redox reactions. However, the discovery of ferroelectricity in doped-HfO2 opens doors to use polarization reversal as a phenomenon to control the resistance. Here, Hf0.5Zr0.5O2 epitaxial ferroelectric tunnel junctions with thickness smaller than 5 nanometers are studied. Electrical and structural analyses have allowed identifying the coexistence of genuine ferroelectric switching and ionic-like motion as mechanisms to induce resistance change in the same junction. By engineering the film’s microstructure, the ferroelectric switching was optimized and the ionic motion was suppressed. In addition, its memristive behavior were. The results presented indicate HZO tunnel junctions are feasible alternatives for application in non-volatile memories.

Supervisors:

  • Josep Fontcuberta, MULFOX, ICMAB, CSIC

 

Josep Fontcuberta, Florencio Sánchez and Ignasi Fina deliver regular talks in the main ferroelectric conference.

The annual International Symposium on Applications of Ferroelectrics (ISAF) is sponsored by the IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society (UFFC-S). The first ISAF meeting was held in 1968; since that time, meetings have been hosted all around the world. The first ISAF meeting held in Japan was in the year 2002 (Nara) and again in 2007.

 

The UFFC-S is one of many societies within the Institute of Electrical and Electronics Engineers (IEEE). UFFC-S has over 2,000 members. As a part of their mission, the UFFC-S sponsors three annual meetings: the ISAF meeting, the International Ultrasonics Symposium (IUS), and the International Frequency Control Symposium (IFCS).

 

The ISAF meetings are coordinated by the Ferroelectrics Standing Committee (FerroCom) of the UFFC-S. In 2017, there were 45 members of FerroCom who come from academia, industry, and non-profits from around the world. FerroCom meets twice per year and representatives from FerroCom and the ferroelectrics scientific community serve many roles on the UFFC-S Administrative Committee.

 

The IEEE UFFC-S is interested in the theory, technology, materials, and applications relating to: the generation, transmission, and detection of ultrasonic waves and related phenomena; medical ultrasound, and associated technologies; ferroelectric, piezoelectric, and piezomagnetic materials; frequency generation and control, timing, and time coordination and distribution. This interest ranges from fundamental studies to the design and/or applications of devices, sensors, systems and manufacturing technologies within the general scope defined above.

 

In this conference Josep Fontcuberta, Florencio Sánchez and Ignasi Fina deliver regular talks on different results related to ferroelectric thin films for applications.

Webpage

isaf-isif-pfm2021.org/

 

2021

REGULAR ORAL PRESENTATIONS

 

“Electroresistance and Ferroelectric Polarization in HZO Films Down to 2 nm “

J. Fontcuberta 

International Symposium on Applications of Ferroelectrics (ISAF).

Virtual, 16-21 May 2021

 

“Optical Switch of Resistance in Ferroelectric Junctions “

I. Fina

International Symposium on Applications of Ferroelectrics (ISAF).

Virtual, 16-21 May 2021

 

“Enhanced Ferroelectric Properties of Epitaxial La-Doped Hf0.5Zr0.5O2 Thin Films “

F. Sánchez 

International Symposium on Applications of Ferroelectrics (ISAF).

Virtual, 16-21 May 2021

 

“Enhanced Stability of Orthorhombic Ferroelectric Phase in HfxZr1-xO2 Films Enabled by
Epitaxial Stabilization “

I .Fina  

International Symposium on Applications of Ferroelectrics (ISAF).

Virtual, 16-21 May 2021

Anne-Claire Robert starting the master thesis with us!

 
Hello! My name is Anne-Claire and I’m from France! I’m a materials chemistry student at Rennes1 University. I’m working with Dr.Florencio Sanchez and Dr.Ignasi Fina to complete my Master degree. After work I enjoy playing video games with friends, travelling, sewing, doing SFX makeup… I don’t have recent picture without mask but I guess that Versailles’ gardens are au good place to represent France! See you!
 

2021

Switchable photovoltaic response in hexagonal LuMnO3 single crystals

Yunwei Sheng, Ignasi Fina, Marin Gospodinov, and Josep Fontcuberta

Appl. Phys. Lett. 118, 232902 (2021);  DOI: doi.org/10.1063/5.0053379

 

Orbital occupancy and hybridization in strained SrVO3 epitaxial films

Mathieu Mirjolet , Hari Babu Vasili, Adrian Valadkhani, José Santiso , Vladislav Borisov, Pierluigi Gargiani, Manuel Valvidares, Roser Valentí , and Josep Fontcuberta

Phys Rev. Materials 5, 095002 (2021);  DOI:doi.org/10.1103/PhysRevMaterials.5.095002

 

Thickness effect on ferroelectric properties of La-doped HfO2 epitaxial films down to 4.5 nm

Tingfeng Song, Romain Bachelet, Guillaume Saint-Girons, Nico Dix, Ignasi Fina and Florencio Sanchez,

J. Mater. Chem. C, 2021.;      DOI:doi.org/10.1039/D1TC02512K

 

Electron–Phonon Coupling and Electron–Phonon Scattering in SrVO3

M. Mirjolet, F. Rivadulla, P. Marsik, V. Borisov, R. Valentí, J. Fontcuberta,

J. Adv. Sci. 2021, 2004207. ;      DOI:doi.org/10.1002/advs.202004207

 

Optical Plasmon Excitations in Transparent Conducting SrNbO3 and SrVO3 Thin Films

Mathieu Mirjolet, Mikko Kataja, Tommi K. Hakala, Philipp Komissinskiy, Lambert Alff, Gervasi Herranz, Josep Fontcuberta

Adv. Opt. Materials First published: 14 June 2021;      DOI:doi.org/10.1002/adom.202100520

 

Stabilization of the Ferroelectric Phase in Epitaxial Hf1–xZrxO2 Enabling Coexistence of Ferroelectric and Enhanced Piezoelectric Properties

Tingfeng Song, Huan Tan, Nico Dix, Rahma Moalla, Jike Lyu, Guillaume Saint-Girons, Romain Bachelet, Florencio Sánchez, and Ignasi Fina

ACS Appl. Electron. Mater. 2021, 3, 5, 2106–2113 (2021);      DOI:doi.org/10.1021/acsaelm.1c00122

 

Critical Effect of Bottom Electrode on Ferroelectricity of Epitaxial Hf0.5Zr0.5O2 Thin Films

Saúl Estandía, Jaume Gazquez, Maria Varela, N. Dix, Mengdi Qian, Raul Solanas, Ignasi Fina and Florencio Sanchez

J. Mater. Chem. C, 9, 3486 – 3492 (2021);      DOI:doi.org/10.1039/D0TC05853J

 

Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices

Ignasi Fina* and Florencio Sánchez*

ACS Appl. Electron. Mater. 2021, 3, 4, 1530-1549;      DOI:doi.org/10.1021/acsaelm.1c00110

 

Non-volatile optical switch of resistance in photoferroelectric tunnel junctions

X.Long, H. Tan, F. Sánchez, I. Fina, J. Fontcuberta

Nature Communications volume 12, Article number: 382 (2021);    DOI:10.1038/s41467-020-20660-9

Non-volatile optical switch of resistance in photoferroelectric tunnel junctions

Xiao Long, Huan Tan, Florencio Sánchez, Ignasi Fina, Josep Fontcuberta

Nature Communications volume 12, Article number: 382 (2021);      DOI:10.1038/s41467-020-20660-9

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 the imprint electric field existing in the nanometric BaTiO3 films and their photovoltaic response at visible light, the polarization of suitably written domains can be reversed under illumination. We exploit this effect to trigger and measure the associate change of resistance in tunnel devices. We show that engineering the device structure by inserting an auxiliary dielectric layer, the electroresistance increases by a factor near 2 × 103%, and a robust electric and optic cycling of the device can be obtained mimicking the operation of a memory device under dual control of light and electric fields.

 

 

Ignasi Fina Three receives an i-Link+ grant for International collaborations

 

Ignasi FinaFlorencio SánchezHuan Tan, and Tingfeng Song, from the Multifunctional Thin Films and Complex Structures (MULFOX) group, are joining forces with the Politecnico di Milano and the University of Cambridge to aid in the ongoing efforts in device miniaturization. They are doing so by trying to face one of the main bottlenecks in the process: heating.

As miniaturized devices become more powerful, it becomes more and more important to find solutions to dissipate the extra heat that comes with it. This team is trying to develop solid materials that can refrigerate the device using the electrocaloric effects that are very pronounced in ferroelectric materials. Ferroelectricity has been recently discovered in hafnium oxide, a CMOS compatible material, but its electrocaloric properties are yet to be investigated.

To further study the properties and applications of hafnium oxide films, Ignasi Fina’s group is pitching in their experience in ferroelectric characterization and material development. They will join the University of Cambridge’s group (UK), led by Xavier Moya, who has experience in the characterization of electrocaloric effects, and the one from Politecnico di Milano (Italy), led by Christian Rinaldi, with experience in device fabrication, in order to reduce the heating and power consumption of small devices.

Thermal evolution of ferroelectric behavior in epitaxial Hf0.5Zr0.5O2

J. W. Adkins, I. Fina, F. Sanchez, S. R. Bakaul, and J. T. Abiade

Appl. Phys. Lett. 117, 142902 (2020);

DOI: 10.1063/5.0015547

 

Abstract

Herein, we report a cryogenic-temperature study on the evolution of the ferroelectric properties of epitaxial Hf0.5Zr0.5O2 thin films on silicon. Wake-up, endurance, and fatigue of these films are found to be intricately correlated, strongly hysteretic, and dependent on available thermal energy. Field-dependent measurements reveal a decrease in polarization with temperature, which has been determined not to be an intrinsic change of the material property, rather a demonstration of the increase in the coercive bias of the material. Our findings suggest that a deficiency in thermal energy suppresses the mobility of defects presumed to be oxygen vacancies during wake-up and trapped injected charge during fatigue, which is responsible for polarization evolution during cycling. This permits accelerated wake-up and fatigue effects at high temperatures where thermal energy is abundant but delays these effects at cryogenic temperatures.

Optically Controlled Ferroelectric Memristors Summer School

We announce the “summer” school on “Optically Controlled Ferroelectric Memristors” (OPTOFEM 2020) goes Online! The School will finally take place on October, 22-23, 2020, in an online format, due to the current COVID-19. Great and experienced lectureres from around the world will participate. Register now before October 11, 2020 to attend! 

All-optically controlled resistive switching could offer advantages, in terms of energy dissipation and speed, for logic and data storage functions in solid-state devices. Ferroelectrics may constitute a building block of this emerging technology, when integrated in nanometric tunnel devices. The functioning of these devices, from photon absorption to the resistive switching involve a subtle interplay between electronic and optical properties, polarization effects and materials issues.

Objective of the school and target audience

The OPTOFEM 2020 school aims at introducing the scientific knowledge, in a tutorial style, required to contribute to this emerging field. Most reputed scientist active in the field will deliver lectures in a strongly interacting atmosphere.

The school is targeting an audience of PhD fellows and researchers initiating their activity on photoresponse in oxides, with interest on polar materials (ferroelectric), with applications spanning from photovoltaics to resistive switching.

Registration

The school will take place on 22-23 October in an online format.

The school will be limited to a maximum of 50 students, selected on the basis of their motivation and recommendation letter provided. Priority will be for PhD fellows and MSc students in the school-related field.

Deadline for registration is October 11, 2020. Registration is through the conference website. 

Invited Lecturers

Organizers

Josep Fontcuberta and Ignasi Fina
Chairs of OPTOFEM 2020
Laboratory of Multifunctional Oxides and Complex Structures (MULFOX)

For additional information and registration, please refer to the conference webpage: optofem2020.icmab.esor contact us by email at optofem2020@icmab.es

Mikko Kataja.

 

 

 

Hello everyone! I’m Mikko Kataja and I come from Finland, where I did my PhD in Aalto University on magneto-optically active plasmonic nanoparticles. I am now in ICMAB in Multifunctional Oxides and Complex Structures research group to explore the possibilities that active oxide materials, such as ferromagnetic and ferroelectric oxides, offer in the field of optics, especially for active nanoscale optical devices. In my freetime, I enjoy cooking and board games.

 

 

 

Engineering Polar Oxyitrides: Hexagonal Perovskite BaWON2

Judith Oró‐Solé, Ignasi Fina, Carlos Frontera, Jaume Gàzquez, Clemens Ritter, Marina Cunquero, Pablo Loza‐Alvarez, Sergio Conejeros, Pere Alemany, , Enric Canadell, Josep Fontcuberta, Amparo Fuertes;

Angew. Chem. Int. Ed. 2020, 59, 18395–18399;      DOI:10.1002/anie.202006519

In the quest for materials of narrow band gap, oxynitrides are excellent candidates. Aiming at obtaining a polar materials of narrow gap, oxynitides are developed here having an hexagonal structure and anion ordering that leads to a non centrosymmetric structures. As such,  here BaWON2 is synthesized and we demonstrate its polar character and large photo absorptivity.