Publications de Bálint Náfrádi

Magnetic structure of the magnetoelectric material Ba2MnGe2O7

A detailed investigation of Ba2MnGe2O7 was performed in its low-temperature magnetoelectric state combining neutron diffraction with magnetization measurements on single crystals. In the paramagnetic state at 10 K, polarized neutron diffraction was applied ...

2023

Magnetic structure of the two-dimensional XY antiferromagnet Sr2CoSi2O7 studied using single-crystal neutron diffraction

Bálint Náfrádi

We report a combined polarized and unpolarized neutron diffraction study on a multiferroic Sr2CoSi2O7 (SCSO) single crystal below and above the antiferromagnetic ordering temperature TN = 6.5 K. Unpolarized neutron diffraction measurements at 15 K confirm ...

AMER PHYSICAL SOC2023

Ultralong 100 ns spin relaxation time in graphite at room temperature

László Forró, Bálint Náfrádi, Péter Szirmai, Bence Gábor Márkus

Graphite has been intensively studied, yet its electron spins dynamics remains an unresolved problem even 70 years after the first experiments. The central quantities, the longitudinal (T-1) and transverse (T-2) relaxation times were postulated to be equal ...

Nature Portfolio2023

Topological Analysis of the Experimental Electron Density in Multiferroic Antiferromagnet Ba2MnGe2O7

Bálint Náfrádi

In the field of magnetoelectric coupling, especially via the spin-dependent metal-ligand d-p hybridization mechanism found in multiferroic Ba2MGe2O7 (M = Mn, Co), detailed knowledge of the microscopic structural parameters is essential, also for the theore ...

Institute of Electrical and Electronics Engineers2022

Ultrasensitive 3D Aerosol-Jet-Printed Perovskite X-ray Photodetector

László Forró, Alla Arakcheeva, Bálint Náfrádi, Endre Horvath, Pavao Roko Andricevic, Anastasiia Glushkova, Márton Kollár

X-ray photon detection is important for a wide range of applications. The highest demand, however, comes from medical imaging, which requires cost-effective, high-resolution detectors operating at low-photon flux, therefore stimulating the search for novel ...

2021

Hybrid halide perovskite neutron detectors

László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Pavel Frajtag, Andreas Pautz, Pavao Roko Andricevic, Márton Kollár

Interest in fast and easy detection of high-energy radiation (x-, gamma-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide pe ...

Nature Portfolio2021

Intermolecular Resonance Correlates Electron Pairs Down a Supermolecular Chain: Antiferromagnetism in K-Doped p-Terphenyl

László Forró, Bálint Náfrádi, Péter Szirmai

Recent interest in potassium-doped p-terphenyl has been fueled by reports of superconductivity at T-c values surprisingly high for organic compounds. Despite these interesting properties, studies of the structure-function relationships within these materia ...

AMER CHEMICAL SOC2020

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

Light-induced charge transfer at the CH3NH3PbI3/TiO2 interface-a low-temperature photo-electron paramagnetic resonance assay

Philippe Bugnon, László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Péter Szirmai, Pavao Roko Andricevic, Anastasiia Glushkova, Márton Kollár, Konstantins Mantulnikovs

The performance of organic-inorganic metal halide perovskites-based (MHPs) photovoltaic devices critically depends on the design and material properties of the interface between the light-harvesting MHP layer and the electron transport layer (ETL). Therefo ...

2020

Kilogram-Scale Crystallogenesis of Halide Perovskites for Gamma-Rays Dose Rate Measurements

László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Pavel Frajtag, Andreas Pautz, Vincent Pierre Lamirand, Pavao Roko Andricevic, Márton Kollár

Gamma-rays (gamma-rays), wherever present, e.g., in medicine, nuclear environment, or homeland security, due to their strong impact on biological matter, should be closely monitored. There is a need for simple, sensitive gamma-ray detectors at affordable p ...

2020

Ultralong Spin Lifetime in Light Alkali Atom Doped Graphene

László Forró, Bálint Náfrádi, Péter Szirmai, Bence Gábor Márkus

Today's great challenges of energy and informational technologies are addressed with a singular compound, Li-and Na-doped few-layer graphene. All that is impossible for graphite (homogeneous and high-level Na doping) and unstable for single-layer graphene ...

AMER CHEMICAL SOC2020

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

Tuning Conductivity and Spin Dynamics in Few-Layer Graphene via In Situ Potassium Exposure

László Forró, Bálint Náfrádi, Péter Szirmai, Olivér Sági, Ferenc Simon, Sándor Kollarics, Bence Gábor Márkus

Chemical modification such as intercalation or doping of novel materials is of great importance for exploratory material science and applications in various fields of physics and chemistry. Herein, the systematic intercalation of chemically exfoliated few- ...

2020

Radiation detection and energy conversion in nuclear reactor environments by hybrid photovoltaic perovskites

László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Endre Horvath, Pavao Roko Andricevic, Márton Kollár

Detection and direct power conversion of high energy and high intensity ionizing radiation could be a key element in next generation nuclear reactor safety systems and space-born devices. For example, the Fukushima catastrophe in 2011 could have been large ...

Elsevier2020

Highly stable enzyme-mimicking nanocomposite of antioxidant activity

Bálint Náfrádi, Marko Pavlovic

A highly stable nanocomposite of antioxidant activity was developed by immobilization of a superoxide dismutase-mimicking metal complex on copolymer-functionalized nanoclay. The layered double hydroxide (LDH) nanoclays were synthesized and surface modifica ...

2019

Improved Alkali Intercalation of Carbonaceous Materials in Ammonia Solution

László Forró, Bálint Náfrádi, Péter Szirmai, Ferenc Simon, Sándor Kollarics, Bence Gábor Márkus

Alkali-intercalated graphite compounds represent a compelling modification of carbon with significant application potential and various fundamentally important phases. The intercalation of graphite with alkali atoms (Li and K) using liquid ammonia solution ...

WILEY-V C H VERLAG GMBH2019

Dry-pressed anodized titania nanotube/CH3NH3PbI3 single crystal heterojunctions: The beneficial role of N doping

László Forró, Bálint Náfrádi, Endre Horvath, Konrad Domanski, Pavao Roko Andricevic, Márton Kollár

Highly ordered, anodically grown TiO2 nanotubes on titanium supports were annealed in ammonia atmosphere in order to incorporate nitrogen doping (

2019

Pressure-induced transformation of CH3NH3PbI3: the role of the noble-gas pressure transmitting media

László Forró, Andrzej Sienkiewicz, Alla Arakcheeva, Bálint Náfrádi, Endre Horvath, Anastasiia Glushkova, Márton Kollár, Gaétan Charles Antoine Giriat

The photovoltaic perovskite, methylammonium lead triiodide [CH3NH3PbI3 (MAPbI(3))], is one of the most efficient materials for solar energy conversion. Various kinds of chemical and physical modifications have been applied to MAPbI(3) towards better unders ...

International Union of Crystallography (IUCr)2019

Light-Emitting Electrochemical Cells of Single Crystal Hybrid Halide Perovskite with Vertically Aligned Carbon Nanotubes Contacts

László Forró, Andrzej Sienkiewicz, Bálint Náfrádi, Tonko Garma, Endre Horvath, Xavier François Mettan, Pavao Roko Andricevic, Márton Kollár

Based on the reported ion migration under an electric field in hybrid lead halide perovskites we have developed a bright, light-emitting electrochemical cell with CH3NH3PbBr3 single crystals directly grown on vertically aligned carbon nanotube forests as c ...

2019

Characterizing the maximum number of layers in chemically exfoliated graphene

László Forró, Bálint Náfrádi, Péter Szirmai, Julian Ayrton Englert, Ferenc Simon, Bence Gábor Márkus

An efficient route to synthesize macroscopic amounts of graphene is highly desired and bulk characterization of such samples, in terms of the number of layers, is equally important. We present a Raman spectroscopy-based method to determine the typical uppe ...

Springer Nature2019