TY - CONF AU - Hajagos-Nagy, Klára AU - Misják, Fanni AU - Lobotka, P AU - Radnóczi, György ED - Steinbach, Gábor TI - CU-MN RÉTEGEK MIKROSZERKEZETE ÉS ELEKTROMOS TULAJDONSÁGAI. Microstructure and electrical properties of Cu-Mn films TS - Microstructure and electrical properties of Cu-Mn films T2 - A Magyar Mikroszkópos Társaság éves konferenciájának kivonatkönyve 2023 : Book of the Abstracts of the Annual Conference of HSM 2023 PY - 2023 SP - 36 EP - 38 PG - 3 UR - https://m2.mtmt.hu/api/publication/34487450 ID - 34487450 N1 - Előadás LA - English DB - MTMT ER - TY - JOUR AU - Lábár, János AU - Hajagos-Nagy, Klára AU - Das, Partha P. AU - Gomez-Perez, Alejandro AU - Radnóczi, György TI - Simple ePDF: A Pair Distribution Function Method Based on Electron Diffraction Patterns to Reveal the Local Structure of Amorphous and Nanocrystalline Materials JF - NANOMATERIALS J2 - NANOMATERIALS-BASEL VL - 13 PY - 2023 IS - 24 PG - 17 SN - 2079-4991 DO - 10.3390/nano13243136 UR - https://m2.mtmt.hu/api/publication/34435393 ID - 34435393 AB - 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. LA - English DB - MTMT ER - TY - CHAP AU - Radnóczi, György ED - Kittel, Ágnes ED - Solymosi, Katalin ED - Barna, László TI - TEM minták ionsugaras vékonyítása Barna Árpádnak, a módszer megalapozójának emlékére. TEM sample preparation by ion milling. Memorial lecture to recall the input of Árpád Barna TS - TEM sample preparation by ion milling. Memorial lecture to recall the input of Árpád Barna T2 - A Magyar Mikroszkópos Társaság 2022 Konferenciájának Kivonatkönyve PB - Magyar Mikroszkópos Társaság CY - Budapest SN - 9786158210706 PY - 2022 SP - 103,118 EP - 105,120 PG - 3 UR - https://m2.mtmt.hu/api/publication/33342203 ID - 33342203 LA - English DB - MTMT ER - TY - CHAP AU - Hajagos-Nagy, Klára AU - Misják, Fanni AU - Radnóczi, György ED - Kittel, Ágnes ED - Solymosi, Katalin ED - Barna, László TI - Cu-Mn szilárd oldat rétegek mikroszerkezetének és morfológiájának kombinatorikus feltérképezése. Combinatorial mapping of microstructure and morphology in Cu-Mn solid solution films TS - Combinatorial mapping of microstructure and morphology in Cu-Mn solid solution films T2 - A Magyar Mikroszkópos Társaság 2022 Konferenciájának Kivonatkönyve PB - Magyar Mikroszkópos Társaság CY - Budapest SN - 9786158210706 PY - 2022 SP - 80 EP - 83 PG - 4 UR - https://m2.mtmt.hu/api/publication/33342162 ID - 33342162 LA - English DB - MTMT ER - TY - JOUR AU - Villy, Lajos Péter AU - Kohut, Attila AU - Kéri, Albert AU - Bélteki, Ádám AU - Radnóczi, György AU - Fogarassy, Zsolt AU - Radnóczi, György Zoltán AU - Galbács, Gábor AU - Geretovszky, Zsolt TI - Continuous spark plasma synthesis of Au/Co binary nanoparticles with tunable properties JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 12 PY - 2022 IS - 1 PG - 9 SN - 2045-2322 DO - 10.1038/s41598-022-22928-0 UR - https://m2.mtmt.hu/api/publication/33208918 ID - 33208918 AB - We present here a scalable and environmentally friendly gas phase technique employing atmospheric pressure electrical spark discharge plasmas for the production of Au/Co binaries, an effective catalyst system for the decomposition of hydrogen-rich compounds, such as ammonium borane. We demonstrate that Au/Co alloy nanoparticles can be produced via the spark plasma-based technique. The possibility of varying the morphology and phase structure via real time heat treatment of the generated aerosol to form Au/Co/CoO particles with continuous control over a wide particle compositional range (from 24 to 64 at.% [Co]/([Co] + [Au]) content) is also demonstrated. Since our spark-based approach is proven to be capable of providing reasonable particle yields, these results may contribute to the transition of lab-scale, nanocatalyst-based hydrogen storage systems to real world applications. LA - English DB - MTMT ER - TY - JOUR AU - Dvurečenskij, A. AU - Cigáň, A. AU - Lobotka, P. AU - Radnóczi, György AU - Škrátek, M. AU - Benyó, Judit Borbála AU - Kováčová, E. AU - Majerová, M. AU - Maňka, J. TI - Colloids of HEA nanoparticles in an imidazolium-based ionic liquid prepared by magnetron sputtering: Structural and magnetic properties JF - JOURNAL OF ALLOYS AND COMPOUNDS J2 - J ALLOY COMPD VL - 896 PY - 2022 PG - 10 SN - 0925-8388 DO - 10.1016/j.jallcom.2021.163089 UR - https://m2.mtmt.hu/api/publication/32530671 ID - 32530671 AB - Colloids consisting of the CoCrCuFeNi high-entropy alloy nanoparticles in ionic liquid with the 1-butyl-3-methylimidazolium ([BMIM]+) cation and the tetrafluorborate ([BF4]-) anion were obtained by the DC magnetron sputtering of high-entropy alloy target in vacuum, onto the surface of [BMIM.BF4] ionic liquid. The method of the nanoparticle colloid preparation is based on negligibly small vapour pressure of the ionic liquid, which allows its application in vacuum. The high-entropy alloy nanoparticle colloids were studied by HRTEM microscopy and SQUID magnetometry. Results of the structural and magnetic analyses show that the colloids contain ultra-small single-crystalline nanoparticles of an uneven shape and typical size of (2−3) nm. The nanoparticles have relatively narrow size distribution which is typical for this preparation method. The high-entropy alloy nanocolloids show complex magnetic properties that are a function of temperature, applied magnetic field and mass content of the nanoparticles in the colloids. The obtained results imply significant magnetic interactions between the ionic liquid and the high-entropy alloy nanoparticles. LA - English DB - MTMT ER - TY - JOUR AU - Radnóczi, György AU - Dedoncker, R. AU - Radnóczi, György Zoltán AU - Czigány, Zsolt AU - Sulyok, Attila AU - Kovácsné Kis, Viktória AU - Depla, D. TI - The growth of a multi-principal element (CoCrFeMnNi) oxynitride film by direct current magnetron sputtering using air as reactive gas JF - SURFACE AND COATINGS TECHNOLOGY J2 - SURF COAT TECH VL - 421 PY - 2021 PG - 13 SN - 0257-8972 DO - 10.1016/j.surfcoat.2021.127433 UR - https://m2.mtmt.hu/api/publication/32078773 ID - 32078773 AB - CoCrFeMnNi multi-principal element alloy films were grown by direct current magnetron sputtering in a mixture of argon and air. The air fraction was varied from 4 to 50%, which resulted in a change of the phase state of the growing film. A 〈100〉 preferred orientation face centered cubic metal (doped with O and N) structure develops below 12% of air. Between 12 and 30% air, a two phase 〈100〉 preferred orientation face centered cubic metal + oxynitride (B1) structure forms. Above 30% of air a single phase B1 oxynitride structure is observed. Compared to nitrogen, oxygen is preferentially incorporated into the growing structures. The 〈100〉 preferential orientation is the result of selective nucleation (below 30% of air) or competing growth (above 30% of air) of the forming crystals. Detailed microscopic analysis shows a complex structure for both the metal and the oxynitride phase in the films deposited at low and high air fraction. In both cases, the films are characterized by local structures ordered on a few nanometer scale and their formation is explained as a result of spinodal decomposition of the as-formed homogenous structure which occurs during film growth. LA - English DB - MTMT ER - TY - JOUR AU - Arfaoui, Mohamed AU - Kovácsné Kis, Viktória AU - Radnóczi, György TI - Diffusionless FCC to BCC phase transformation in CoCrCuFeNi MPEA thin films JF - JOURNAL OF ALLOYS AND COMPOUNDS J2 - J ALLOY COMPD VL - 863 PY - 2021 PG - 10 SN - 0925-8388 DO - 10.1016/j.jallcom.2021.158712 UR - https://m2.mtmt.hu/api/publication/31823041 ID - 31823041 AB - The aim of the present work is growing CoCrCuFeNi HEA thin films of 40–50 nm thickness and annealing them in-situ in the electron microscope for a better understanding and controlling the early stages of phase and compositional instability of as deposited films at temperatures up to 550 °C. Carrying out in-situ electron microscopic experiments of isochronal annealing at temperatures of 450 °C and 550 °C we could follow the structural changes in thin (40–50 nm thick) CoCrCuFeNi MPEA films. We observed that at temperatures 450 and 550 °C the first change in the structure is the martensitic transformation of the FCC to BCC phase. We have shown by EDS mapping of the transformed area that no compositional changes occur during this process and, specific for martensitic transformation orientation, relationships between the two phases are present. The changes occur after about 20 min annealing time at these temperatures. Longer anneals at the same temperatures lead to separation of components. Above 40 min annealing time at 450 °C voids appear in the film, Cr will be partly bonded to oxygen (impurity in the vacuum system) in the form of a thin surface oxide layer. The other components tend to form binary like compositions of Cu-Ni and Fe–Co pairs. We also estimated the diffusion coefficient at 450 °C in this alloy to be around ~6 × 10−19 m2/s. LA - English DB - MTMT ER - TY - JOUR AU - Gubicza, Jenő AU - Garima, Kapoor AU - Ugi, Dávid AU - Péter, László AU - Lábár, János AU - Radnóczi, György TI - Micropillar compression study on the deformation behavior of electrodeposited Ni-Mo films JF - COATINGS J2 - COATINGS VL - 10 PY - 2020 IS - 3 SP - 21 EP - 34 PG - 14 SN - 2079-6412 DO - 10.3390/coatings10030205 UR - https://m2.mtmt.hu/api/publication/31282736 ID - 31282736 LA - English DB - MTMT ER - TY - JOUR AU - Arfaoui, Mohamed AU - Radnóczi, György AU - Kovácsné Kis, Viktória TI - Transformations in CrFeCoNiCu High Entropy Alloy Thin Films during In-Situ Annealing in TEM JF - COATINGS J2 - COATINGS VL - 10 PY - 2020 IS - 1 PG - 15 SN - 2079-6412 DO - 10.3390/coatings10010060 UR - https://m2.mtmt.hu/api/publication/31136772 ID - 31136772 LA - English DB - MTMT ER -