Publications de Andrea Pisoni | EPFL Graph Search

Tuning ferromagnetism at room temperature by visible light

László Forró, Bálint Náfrádi, Massimo Spina, Endre Horvath, Xavier François Mettan, Andrea Pisoni, Péter Szirmai

Most digital information today is encoded in the magnetization of ferromagnetic domains. The demand for ever-increasing storage space fuels continuous research for energy-efficient manipulation of magnetism at smaller and smaller length scales. Writing a b ...

National Academy of Sciences2020

Preferential out-of-plane conduction and quasi-one-dimensional electronic states in layered 1T-TaS2

Helmuth Berger, László Forró, Alla Arakcheeva, Ana Akrap, Luka Ciric, Andrea Pisoni, Edoardo Martino, Philip Johannes Walter Moll, Matthias Carsten Putzke, Konstantin Semeniuk

Layered transition metal dichalcogenides (TMDs) are commonly classified as quasi-two-dimensional materials, meaning that their electronic structure closely resembles that of an individual layer, which results in resistivity anisotropies reaching thousands. ...

2020

Quantum spin-liquid states in an organic magnetic layer and molecular rotor hybrid

László Forró, Bálint Náfrádi, Andrea Pisoni, Péter Szirmai, Edoardo Martino, Konstantins Mantulnikovs

The exotic properties of quantum spin liquids (QSLs) have continually been of interest since Anderson's 1973 ground-breaking idea. Geometrical frustration, quantum fluctuations, and low dimensionality are the most often evoked material's characteristics th ...

National Academy of Sciences2020

Tailoring thermal conduction in anatase TiO2

Luca Rossi, Helmuth Berger, László Forró, Jacim Jacimovic, Endre Horvath, Xavier François Mettan, Andrea Pisoni, Péter Szirmai

Thermal conductivity (κ) plays an essential role in functional devices. It is advantageous to design materials where one can tune κ in a wide range according to its function: single-crystals and nanowires of anatase polymorph of titanium dioxide, broadly u ...

Springer2019

The influence of the incommensurately modulated structure on the physical properties of Fe1.35Ge

Helmuth Berger, László Forró, Alla Arakcheeva, Philip Pattison, Krunoslav Prsa, Jacim Jacimovic, Sergiy Katrych, Andrea Pisoni

Single crystal growth by chemical vapour transport has resulted samples with Fe1.35Ge stoichiometry. Structural study has shown that the large number of vacancies introduces an incommensuately modulated structure. The electrical resistivity is in the 200 m ...

2019

Mapping the lattice dynamical anomaly of the order parameters across the Verwey transition in magnetite

Henrik Moodysson Rønnow, Fabrizio Carbone, Andrea Pisoni, Francesco Pennacchio, Simone Borroni, Gregory Scott Tucker

We present inelastic neutron scattering data across the Verwey transition in magnetite, obtained for a single crystal via a detwinning method. We provide direct evidence of the influence of the charge order on the transverse-acoustic phonons, associated wi ...

2017

Charge-Stripe Order and Superconductivity in Ir1−xPtxTe2

László Forró, Henrik Moodysson Rønnow, Yixing Chen, Johan Juul Chang, Andrea Pisoni, Lin Yang, Péter Krisztián Matus, Edoardo Martino

A combined resistivity and hard x-ray diffraction study of superconductivity and charge ordering in Ir Ir1−xPtxTe2, as a function of Pt substitution and externally applied hydrostatic pressure, is presented. Experiments are focused on samples near the crit ...

Nature Research2017

Photodiode Response in a CH3NH3PbI3/CH3NH3SnI3 Heterojunction

László Forró, Bálint Náfrádi, Massimo Spina, Endre Horvath, Karoly Holczer, Andrea Pisoni

Here we report another surprising feature of the methylammonium metal halide material family, the phototunability of the diode response of a heterojunction made of CH3NH3PbI3 and its close relative, CH3NH3SnI3. In the dark state the device behaves as a dio ...

2017

Possibility of an unconventional spin state of Ir4+ in Ba21Ir9O43 single crystal

László Forró, Arnaud Magrez, Oleg Yazyev, Alla Arakcheeva, Bálint Náfrádi, Henrik Moodysson Rønnow, Ivica Zivkovic, Jacim Jacimovic, Sergiy Katrych, Andrea Pisoni, Lin Yang, Noore Elahi Shaik

We report the synthesis of single crystals of a novel layered iridate Ba21Ir9O43 and present the crystallographic, transport, and magnetic properties of this material. The compound has a hexagonal structure with two iridium oxide layers stacked along the c ...

Amer Physical Soc2016

A novel quasi-one-dimensional topological insulator in bismuth iodide beta-Bi4I4

László Forró, Marco Grioni, Oleg Yazyev, Luca Moreschini, Gabriel Albert Autes, Jens Christian Johannsen, Andrea Pisoni, Wentao Zhang

Recent progress in the field of topological states of matter(1,2) has largely been initiated by the discovery of bismuth and antimony chalcogenide bulk topological insulators (TIs; refs 3-6), followed by closely related ternary compounds(7-16) and predicti ...

Nature Publishing Group2016

Pressure-tuned Transport Properties of Novel Iron-based Superconductors and Topological Insulators

Andrea Pisoni

The majority of interactions in solids strongly depend on the interatomic distances. The application of pressure changes the lattice parameters and modifies the electronic and the phononic energy spectra of a material avoiding some of the undesirable effec ...

EPFL2016

Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm4Fe2As2Te1-xO4-yFy

László Forró, Richard Gaal, Bálint Náfrádi, Sergiy Katrych, Janusz Andrzej Karpinski, Andrea Pisoni, Péter Szirmai

We present a detailed study of the electrical transport properties of a recently discovered iron-based superconductor: Sm4Fe2As2Te0.72O2.8F1.2. We followed the temperature dependence of the upper critical field by resistivity measurement of single crystals ...

Iop Publishing Ltd2016

Magnetotransport studies of superconducting Pr4Fe2As2Te1-xO4

László Forró, Richard Gaal, Bálint Náfrádi, Sergiy Katrych, Janusz Andrzej Karpinski, Andrea Pisoni, Péter Szirmai

We report a study of the electrical transport properties of single crystals of Pr(4)Fe(2)As(2)Te(1-)xO(4), a recently discovered iron-based superconductor. Resistivity, Hall effect, and magnetoresistance are measured in a broad temperature range revealing ...

Amer Physical Soc2016

Single crystals of superconducting SmFeAsOHx: Structure and properties

László Forró, Richard Gaal, Alla Arakcheeva, Sergiy Katrych, Janusz Andrzej Karpinski, Andrea Pisoni, Ping Huang, Péter Krisztián Matus

We report the synthesis, structure, and superconducting properties of single crystals of SmFeAsOHx. The crystals were grown at high pressure and high temperature using a cubic anvil technique. H-1-NMR studies confirm the presence of H atoms in the samples. ...

Amer Physical Soc2016

Anisotropic transport properties of tungsten disulfide

Helmuth Berger, László Forró, Richard Gaal, Bálint Náfrádi, Jacim Jacimovic, Andrea Pisoni

Single crystals of WS2 were prepared by chemical vapor transport method using sulfur as a transport agent. Measurements of electrical resistivity, Seebeck coefficient and thermal conductivity as a function of temperature, along the in-plane and the out-of- ...

Pergamon-Elsevier Science Ltd2016

Challenges and Rewards of the Electrosynthesis of Macroscopic Aligned Carbon Nanotube Array/Conducting Polymer Hybrid Assemblies

László Forró, Klara Hernadi, Endre Horvath, Andrea Pisoni, Péter Krisztián Matus

Hybrid assemblies based on conducting polymers and carbon nanomaterials with organized nanoscale structure are excellent candidates for various application schemes ranging from thermal management to electrochemical energy conversion and storage. In the cas ...

Wiley-Blackwell2015

Crystal Structure, Transport, and Magnetic Properties of an Ir6+ Compound Ba8Al2IrO14

László Forró, Arnaud Magrez, Alla Arakcheeva, Bastien Dalla Piazza, Ana Akrap, Krunoslav Prsa, Henrik Moodysson Rønnow, Jacim Jacimovic, Sergiy Katrych, Andrea Pisoni, Lin Yang

The novel iridate Ba8Al2IrO14 was prepared as single crystals by self-flux method, thereby providing a rare example of an all-Ir(VI) compound that can be synthesized under ambient pressure conditions. The preparation of all-Ir6+ iridate without using tradi ...

2015

Tuning of the Thermoelectric Figure of Merit of CH3NH3MI3 (M=Pb,Sn) Photovoltaic Perovskites

László Forró, Davor Pavuna, Bálint Náfrádi, Massimo Spina, Endre Horvath, Xavier François Mettan, Andrea Pisoni, Péter Krisztián Matus, Riccardo Pisoni

The hybrid halide perovskites, the very performant compounds in photovoltaic applications, possess large Seebeck coefficient and low thermal conductivity, making them potentially interesting high figure of merit (ZT) materials. For this purpose, one needs ...

American Chemical Society2015

The Role of Transport Agents in MoS2 Single Crystals

Helmuth Berger, László Forró, Arnaud Magrez, Bálint Náfrádi, Arnaud Walter, Jacim Jacimovic, Andrea Pisoni

We report resistivity, thermoelectric power, and thermal conductivity of MoS2 single crystals prepared by the chemical vapor transport (CVT) method using I-2, Br-2, and TeCl4 as transport agents. The material presents low-lying donor and acceptor levels, w ...

Amer Chemical Soc2015

Electrical conduction of photo-patternable SU8-graphene composites

László Forró, Claudio Grimaldi, Arnaud Magrez, Maryam Majidian, Andrea Pisoni

Graphene-based SU8 nanocomposite is developed as a new conductive polymer, which benefits from remarkable electrical conductivity of graphene, along with photo-pattern-ability and transparency of SU8. Well defined structures with minimal resolution of 10 m ...

Pergamon-Elsevier Science Ltd2014