@article{MTMT:34727542,
	title = {Transzmissziós elektronmikroszkópia az MFA-ban},
	url = {https://m2.mtmt.hu/api/publication/34727542},
	author = {Lábár, János and Pécz, Béla},
	journal-iso = {FIZIKAI SZEMLE},
	journal = {FIZIKAI SZEMLE},
	volume = {74},
	unique-id = {34727542},
	issn = {0015-3257},
	year = {2024},
	pages = {84-87},
	orcid-numbers = {Lábár, János/0000-0002-3944-8350; Pécz, Béla/0000-0002-4651-6972}
}

@CONFERENCE{MTMT:34487551,
	title = {SZUPRAVEZETŐ SZILÍCIUM. Superconducting Silicon},
	url = {https://m2.mtmt.hu/api/publication/34487551},
	author = {Lábár, János and Pécz, Béla and Sulyok, Attila and Chiod, F},
	booktitle = {A Magyar Mikroszkópos Társaság éves konferenciájának kivonatkönyve 2023 : Book of the Abstracts of the Annual Conference of HSM 2023},
	unique-id = {34487551},
	year = {2023},
	pages = {54-56},
	orcid-numbers = {Lábár, János/0000-0002-3944-8350; Pécz, Béla/0000-0002-4651-6972}
}

@article{MTMT:34435393,
	title = {Simple ePDF: A Pair Distribution Function Method Based on Electron Diffraction Patterns to Reveal the Local Structure of Amorphous and Nanocrystalline Materials},
	url = {https://m2.mtmt.hu/api/publication/34435393},
	author = {Lábár, János and Hajagos-Nagy, Klára and Das, Partha P. and Gomez-Perez, Alejandro and Radnóczi, György},
	doi = {10.3390/nano13243136},
	journal-iso = {NANOMATERIALS-BASEL},
	journal = {NANOMATERIALS},
	volume = {13},
	unique-id = {34435393},
	abstract = {Amorphous, glassy or disordered materials play important roles in developing structural materials from metals or ceramics, devices from semiconductors or medicines from organic compounds. Their local structure is frequently similar to crystalline ones. A computer program is presented here that runs under the Windows operating system on a PC to extract pair distribution function (PDF) from electron diffraction in a transmission electron microscope (TEM). A polynomial correction reduces small systematic deviations from the expected average Q-dependence of scattering. Neighbor distance and coordination number measurements are supplemented by either measurement or enforcement of number density. Quantification of similarity is supported by calculation of Pearson’s correlation coefficient and fingerprinting. A rough estimate of fractions in a mixture is computed by multiple least-square fitting using the PDFs from components of the mixture. PDF is also simulated from crystalline structural models (in addition to measured ones) to be used in libraries for fingerprinting or fraction estimation. Crystalline structure models for simulations are obtained from CIF files or str files of ProcessDiffraction. Data from inorganic samples exemplify usage. In contrast to previous free ePDF programs, our stand-alone program does not need a special software environment, which is a novelty. The program is available from the author upon request.},
	keywords = {GLASS; nanocrystals; DECOMPOSITION; automation; TEM; electron diffraction; Coordination number; Disordered materials; PDF; nearest-neighbor distance},
	year = {2023},
	eissn = {2079-4991},
	orcid-numbers = {Lábár, János/0000-0002-3944-8350; Radnóczi, György/0000-0002-5056-7625}
}

@article{MTMT:34332659,
	title = {Superconductivity in laser-annealed monocrystalline silicon films: The role of boron implant},
	url = {https://m2.mtmt.hu/api/publication/34332659},
	author = {Dumas, P. and Opprecht, M. and Kerdilès, S. and Lábár, János and Pécz, Béla and Lefloch, F. and Nemouchi, F.},
	doi = {10.1063/5.0166870},
	journal-iso = {APPL PHYS LETT},
	journal = {APPLIED PHYSICS LETTERS},
	volume = {123},
	unique-id = {34332659},
	issn = {0003-6951},
	year = {2023},
	eissn = {1077-3118},
	orcid-numbers = {Lábár, János/0000-0002-3944-8350; Pécz, Béla/0000-0002-4651-6972}
}

@article{MTMT:33731168,
	title = {Statistical properties of fractal type dislocation cell structures},
	url = {https://m2.mtmt.hu/api/publication/33731168},
	author = {Lipcsei, Sándor and Kalácska, Szilvia and Ispánovity, Péter Dusán and Lábár, János and Dankházi, Zoltán and Groma, István},
	doi = {10.1103/PhysRevMaterials.7.033604},
	journal-iso = {PHYS REV MAT},
	journal = {PHYSICAL REVIEW MATERIALS},
	volume = {7},
	unique-id = {33731168},
	issn = {2475-9953},
	year = {2023},
	eissn = {2475-9953},
	orcid-numbers = {Lipcsei, Sándor/0000-0003-2220-105X; Kalácska, Szilvia/0000-0001-5601-5859; Ispánovity, Péter Dusán/0000-0002-9956-0061; Lábár, János/0000-0002-3944-8350; Dankházi, Zoltán/0000-0001-9545-2015; Groma, István/0000-0002-6644-1365}
}

@article{MTMT:33698442,
	title = {Strain Measurement in Single Crystals by 4D-ED},
	url = {https://m2.mtmt.hu/api/publication/33698442},
	author = {Lábár, János and Pécz, Béla and van, Waveren Aiken and Hallais, Géraldine and Desvignes, Léonard and Chiodi, Francesca},
	doi = {10.3390/nano13061007},
	journal-iso = {NANOMATERIALS-BASEL},
	journal = {NANOMATERIALS},
	volume = {13},
	unique-id = {33698442},
	abstract = {A new method is presented to measure strain over a large area of a single crystal. The 4D-ED data are collected by recording a 2D diffraction pattern at each position in the 2D area of the TEM lamella scanned by the electron beam of STEM. Data processing is completed with a new computer program (available free of charge) that runs under the Windows operating system. Previously published similar methods are either commercial or need special hardware (electron holography) or are based on HRTEM, which involves limitations with respect to the size of the field of view. All these limitations are overcome by our approach. The presence of defects results in small local changes in orientation that change the subset of experimentally available diffraction spots in the individual patterns. Our method is based on a new principle, namely fitting a lattice to (a subset of) measured diffraction spots to improve the precision of the measurement. Although a spot to be measured may be missing in some of the patterns even the missing spot can be precisely measured by the lattice determined from the available spots. Application is exemplified by heavily boron-doped silicon with intended usage as a low-temperature superconductor in qubits.},
	keywords = {Stem; Strain components; reciprocal space lattice fitting; free computer program; superconducting silicon; concentration of substitutional atom; boron in silicon},
	year = {2023},
	eissn = {2079-4991},
	orcid-numbers = {Lábár, János/0000-0002-3944-8350; Pécz, Béla/0000-0002-4651-6972}
}

@{MTMT:33342457,
	title = {A TEM szerepe a Qubitek fejlesztésében. Role of TEM in the development of Qubits},
	url = {https://m2.mtmt.hu/api/publication/33342457},
	author = {Lábár, János and Pécz, Béla and Francesca, Chiodi and Fabrice, Nemouchi and Zhen, Zhang and Shi-Li, Zhang and François, Lefloch},
	booktitle = {A Magyar Mikroszkópos Társaság 2022 Konferenciájának Kivonatkönyve},
	unique-id = {33342457},
	year = {2022},
	pages = {146-149},
	orcid-numbers = {Lábár, János/0000-0002-3944-8350; Pécz, Béla/0000-0002-4651-6972}
}

@article{MTMT:33187153,
	title = {Influence of Degree of Severe Plastic Deformation on Thermal Stability of an HfNbTiZr Multi-Principal Element Alloy Processed by High-Pressure Torsion},
	url = {https://m2.mtmt.hu/api/publication/33187153},
	author = {Hung, Pham Tran and Kawasaki, Megumi and Szabo, Abel and Lábár, János and Hegedus, Zoltan and Gubicza, Jenő},
	doi = {10.3390/nano12193371},
	journal-iso = {NANOMATERIALS-BASEL},
	journal = {NANOMATERIALS},
	volume = {12},
	unique-id = {33187153},
	abstract = {Severe plastic deformation (SPD) is an effective route for the nanocrystallization of multi-principal element alloys (MPEAs). The stability of the refined microstructure is important, considering the high temperature applications of these materials. In the present study, the effect of SPD on the stability of a body-centered cubic (bcc) HfNbTiZr MPEA was investigated. SPD was performed using a high-pressure torsion (HPT) technique by varying the number of turns between 1/2 and 10. The evolution of phase composition and microstructure was studied near the disk centers and edges where the imposed strain values were the lowest and highest, respectively. Thus, the shear strain caused by HPT varies between 3 (1/2 turn, near the center) and 340 (10 turns, near the edge). It was found that during annealing up to 1000 K, the bcc HfNbTiZr alloy decomposed into two bcc phases with different lattice constants at 740 K. In addition, at high strains a hexagonal close packed (hcp) phase was formed above 890 K. An inhomogeneous elemental distribution was developed at temperatures higher than 890 K due to the phase decomposition. The scale of the chemical heterogeneities decreased from about 10 mu m to 30 nm where the shear strain increased from 3 to 340, which is similar to the magnitude of grain refinement. Anneal-induced hardening was observed in the MPEA after HPT for both low and high strains at 740 K, i.e., the hardness of the HPT-processed samples increased due to heat treatment. At low strain, the hardness remained practically unchanged between 740 and 1000 K, while for the alloy receiving high strains there was a softening in this temperature range.},
	keywords = {DISLOCATIONS; annealing; hardness; severe plastic deformation; HfNbTiZr multi-principal element alloy},
	year = {2022},
	eissn = {2079-4991},
	orcid-numbers = {Kawasaki, Megumi/0000-0003-0028-3007; Lábár, János/0000-0002-3944-8350; Gubicza, Jenő/0000-0002-8938-7293}
}

@article{MTMT:33118481,
	title = {Relating the magnetic coercivity to the L10 ordered FePd phase in annealed FexPd100-x nanoparticles},
	url = {https://m2.mtmt.hu/api/publication/33118481},
	author = {Luong, Nguyen Hoang and Trung, Truong Thanh and Hong, Tran Thi and Nam, Nguyen Hoang and Phan, Manh-Huong and Jenei, Péter and Lábár, János and Gubicza, Jenő},
	doi = {10.1007/s00339-022-06059-x},
	journal-iso = {APPL PHYS A-MATER},
	journal = {APPLIED PHYSICS A - MATERIALS SCIENCE AND PROCESSING},
	volume = {128},
	unique-id = {33118481},
	issn = {0947-8396},
	abstract = {Rare-earth-free or iron-based permanent nanomagnets are emerging as promising candidates for energy-conversion and information technologies. In this interest, FexPd100-x nanoparticles (x = 50, 55, 60, and 63) were prepared from iron acetate and palladium acetate by sonoelectrodeposition. After annealing the nanoparticles at various temperatures from 450 to 700 °C for 1 h, structural changes were observed, and the samples exhibit hard magnetic properties that depend strongly on chemical composition and annealing temperature. The major phase in the as-prepared nanoparticles has a disordered face-centered cubic structure, which, upon annealing, transforms into a multi-phase material containing a L10 ordered FePd phase. The fractions of different phases present in the annealed samples, including that of the L10 phase as functions of chemical composition and annealing temperature, are quantified by means of X-ray diffraction and scanning transmission electron microscopy. Magnetic measurements show the desirable hard magnetic properties for the samples annealed at 550–600 °C. A correlation between the magnetic coercivity and the L10 ordered FePd phase fraction is established for the first time in the FexPd100-x nanoparticles.},
	year = {2022},
	eissn = {1432-0630},
	orcid-numbers = {Jenei, Péter/0000-0001-5187-9893; Lábár, János/0000-0002-3944-8350; Gubicza, Jenő/0000-0002-8938-7293}
}

@article{MTMT:32770846,
	title = {Combinatorial Study of Phase Composition, Microstructure and Mechanical Behavior of Co-Cr-Fe-Ni Nanocrystalline Film Processed by Multiple-Beam-Sputtering Physical Vapor Deposition.},
	url = {https://m2.mtmt.hu/api/publication/32770846},
	author = {Nagy, Péter and Rohbeck, Nadia and Widmer, Remo N and Hegedűs, Zoltán and Michler, Johann and Pethö, László and Lábár, János and Gubicza, Jenő},
	doi = {10.3390/ma15062319},
	journal-iso = {MATERIALS},
	journal = {MATERIALS},
	volume = {15},
	unique-id = {32770846},
	abstract = {A combinatorial Co-Cr-Fe-Ni compositional complex alloy (CCA) thin film disk with a thickness of 1 µm and a diameter of 10 cm was processed by multiple-beam-sputtering physical vapor deposition (PVD) using four pure metal sources. The chemical composition of the four constituent elements varied between 4 and 64 at.% in the film, depending on the distance from the four PVD sources. The crystal structure, the crystallite size, the density of lattice defects (e.g., dislocations and twin faults) and the crystallographic texture were studied as a function of the chemical composition. It was found that in a wide range of elemental concentrations a face-centered cubic (fcc) structure with {111} crystallographic texture formed during PVD. Considering the equilibrium phase diagrams, it can be concluded that mostly the phase composition of the PVD layer is far from the equilibrium. Body-centered cubic (bcc) and hexagonal-close packed (hcp) structures formed only in the parts of the film close to Co-Fe and Co-Cr sources, respectively. A nanocrystalline microstructure with the grain size of 10-20 nm was developed in the whole layer, irrespective of the chemical composition. Transmission electron microscopy indicated a columnar growth of the film during PVD. The density of as-grown dislocations and twin faults was very high, as obtained by synchrotron X-ray diffraction peak profile analysis. The nanohardness and the elastic modulus were determined by indentation for the different chemical compositions on the combinatorial PVD film. This study is the continuation of a former research published recently in Nagy et al., Materials 14 (2021) 3357. In the previous work, only the fcc part of the sample was investigated. In the present paper, the study was extended to the bcc, hcp and multiphase regions.},
	keywords = {microstructure; hardness; elastic modulus; multiple-beam-sputtering physical vapor deposition; compositional complex alloy},
	year = {2022},
	eissn = {1996-1944},
	orcid-numbers = {Nagy, Péter/0000-0003-4266-0384; Lábár, János/0000-0002-3944-8350; Gubicza, Jenő/0000-0002-8938-7293}
}