TY - JOUR AU - Stichleutner, Sándor AU - Herczeg, Bence AU - Pechoušek, Jiří AU - Machala, Libor AU - Homonnay, Zoltán AU - Smrčka, David AU - Kouřil, Lukáš AU - Vondrášek, René AU - Kudor, Mátyás AU - Skuratov, Vladimir A. AU - Krupa, Luboš AU - Kubuki, Shiro AU - Kuzmann, Ernő TI - Change in Superparamagnetic State Induced by Swift Heavy Ion Irradiation in Nano-Maghemite JF - METALS J2 - METALS-BASEL VL - 14 PY - 2024 IS - 4 SP - 421 SN - 2075-4701 DO - 10.3390/met14040421 UR - https://m2.mtmt.hu/api/publication/34776265 ID - 34776265 AB - The effect of swift heavy ion irradiation on sol–gel-prepared maghemite nanoparticles was studied by 57Fe transmission Mössbauer spectroscopy and X-ray diffractometry (XRD). The room temperature Mössbauer spectra of the non-irradiated nano-maghemite showed poorly resolved magnetically split, typical relaxation spectra due to the superparamagnetic state of the nanoparticles. Significant changes in the line shape, indicating changes in the superparamagnetic state, were found in the Mössbauer spectra upon irradiation by 160 MeV and 155 MeV 132Xe26+ ions with fluences of 5 × 1013 ion cm−2 and 1 × 1014 ion cm−2. XRD of the irradiated maghemite nanoparticles showed a significant broadening of the corresponding lines, indicating a decrease in the crystallite size, compared to those of the non-irradiated ones. The results are discussed in terms of the defects induced by irradiation and the corresponding changes related to the change in particle size and consequently in the superparamagnetic state caused by irradiation. LA - English DB - MTMT ER - TY - JOUR AU - Béres, Kende Attila AU - Dürvanger, Zsolt AU - Homonnay, Zoltán AU - Nagyné Bereczki, Laura AU - Barta Holló, Berta AU - Farkas, Attila AU - Petruševski, Vladimir M. AU - Kótai, László TI - Insight into the Structure and Redox Chemistry of [Carbonatotetraamminecobalt(III)] Permanganate and Its Monohydrate as Co-Mn-Oxide Catalyst Precursors of the Fischer-Tropsch Synthesis JF - INORGANICS J2 - INORGANICS VL - 12 PY - 2024 IS - 4 SP - 94 SN - 2304-6740 DO - 10.3390/inorganics12040094 UR - https://m2.mtmt.hu/api/publication/34753165 ID - 34753165 AB - [Carbonatotetraamminecobalt(III)] permanganate monohydrate was synthesized first in the metathesis reaction of [Co(NH3)4CO3]NO3 and NaMnO4 in aqueous solution. Its thermal dehydration at 100 °C resulted in phase-pure [Co(NH3)4CO3]MnO4 (compound 1). Compounds 1 and 2 (i.e., the hydrated form) were studied with IR, far-IR, and low-temperature Raman spectroscopies, and their vibrational modes were assigned. The lattice parameters were determined by powder X-ray diffraction (PXRD) and single crystal X-ray diffraction (SXRD) methods for the triclinic and orthorhombic compounds 1 and 2, respectively. The detailed structure of compound 2 was determined, and the role of hydrogen bonds in the structural motifs was clarified. UV studies on compounds 1 and 2 showed the distortion of the octahedral geometry of the complex cation during dehydration because of the partial loss of the hydrogen bonds between the crystal water and the ligands of the complex cation. The thermal decomposition consists of a solid phase quasi-intramolecular redox reaction between the ammonia ligands and permanganate anions with the formation of ammonia oxidation products (H2O, NO, N2O, and CO2). The solid phase reaction product is amorphous cobalt manganese oxide containing ammonium, carbonate (and nitrate) anions. The temperature-controlled thermal decomposition of compound 2 in toluene at 110 °C showed that one of the decomposition intermediates is ammonium nitrate. The decomposition intermediates are transformed into Co1.5Mn1.5O4 spinel with MnCo2O4 structure upon further heating. Solid compound 2 gave the spinel at 500 °C both in an inert and air atmosphere, whereas the sample pre-treated in toluene at 110 °C without and with the removal of ammonium nitrate by aqueous washing, gave the spinel already at 300 and 400 °C, respectively. The molten NH4NO3 is a medium to start spinel crystallization, but its decomposition stops further crystal growth of the spinel phase. By this procedure, the particle size of the spinel product as low as ~4.0 nm could be achieved for the treatments at 300 and 400 °C, and it increased only to 5.7 nm at 500 °C. The nano-sized mixed cobalt manganese oxides are potential candidates as Fischer-Tropsch catalysts. LA - English DB - MTMT ER - TY - JOUR AU - Béres, Kende Attila AU - Homonnay, Zoltán AU - Kótai, László TI - Hexakis(urea-O)iron Complex Salts as a Versatile Material Family: Overview of Their Properties and Applications JF - ACS OMEGA J2 - ACS OMEGA VL - 9 PY - 2024 IS - 10 SP - 11148 EP - 11167 PG - 20 SN - 2470-1343 DO - 10.1021/acsomega.3c09635 UR - https://m2.mtmt.hu/api/publication/34718662 ID - 34718662 N1 - Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar Tudósok krt. 2., Budapest, H-1117, Hungary Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter s. 1/A, Budapest, H-1117, Hungary Export Date: 19 March 2024 Correspondence Address: Béres, K.A.; Institute of Materials and Environmental Chemistry, Magyar Tudósok krt. 2., Hungary; email: beres.kende.attila@ttk.hu Correspondence Address: Kótai, L.; Institute of Materials and Environmental Chemistry, Magyar Tudósok krt. 2., Hungary; email: kotai.laszlo@ttk.hu LA - English DB - MTMT ER - TY - JOUR AU - Ibrahim, Ahmed AU - Tani, Kaoru AU - Hashi, Kanae AU - Zhang, Bofan AU - Homonnay, Zoltán AU - Kuzmann, Ernő AU - Bafti, Arijeta AU - Pavić, Luka AU - Krehula, Stjepko AU - Marciuš, Marijan AU - Kubuki, Shiro TI - Debye Temperature Evaluation for Secondary Battery Cathode of α-SnxFe1−xOOH Nanoparticles Derived from the 57Fe- and 119Sn-Mössbauer Spectra JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 25 PY - 2024 IS - 5 SN - 1661-6596 DO - 10.3390/ijms25052488 UR - https://m2.mtmt.hu/api/publication/34684508 ID - 34684508 AB - Debye temperatures of α-SnxFe1−xOOH nanoparticles (x = 0, 0.05, 0.10, 0.15 and 0.20, abbreviated as Sn100x NPs) prepared by hydrothermal reaction were estimated with 57Fe- and 119Sn-Mössbauer spectra measured by varying the temperature from 20 to 300 K. Electrical properties were studied by solid-state impedance spectroscopy (SS-IS). Together, the charge–discharge capacity of Li- and Na-ion batteries containing Sn100x NPs as a cathode were evaluated. 57Fe-Mössbauer spectra of Sn10, Sn15, and Sn20 measured at 300 K showed only one doublet due to the superparamagnetic doublet, while the doublet decomposed into a sextet due to goethite at the temperature below 50 K for Sn 10, 200 K for Sn15, and 100 K for Sn20. These results suggest that Sn10, Sn15 and Sn20 had smaller particles than Sn0. On the other hand, 20 K 119Sn-Mössbauer spectra of Sn15 were composed of a paramagnetic doublet with an isomer shift (δ) of 0.24 mm s−1 and quadrupole splitting (∆) of 3.52 mm s−1. These values were larger than those of Sn10 (δ: 0.08 mm s−1, ∆: 0.00 mm s−1) and Sn20 (δ: 0.10 mm s−1, ∆: 0.00 mm s−1), suggesting that the SnIV-O chemical bond is shorter and the distortion of octahedral SnO6 is larger in Sn15 than in Sn10 and Sn20 due to the increase in the covalency and polarization of the SnIV-O chemical bond. Debye temperatures determined from 57Fe-Mössbauer spectra measured at the low temperature were 210 K, 228 K, and 250 K for Sn10, Sn15, and Sn20, while that of α-Fe2O3 was 324 K. Similarly, the Debye temperature of 199, 251, and 269 K for Sn10, Sn15, and Sn20 were estimated from the temperature-dependent 119Sn-Mössbauer spectra, which were significantly smaller than that of BaSnO3 (=658 K) and SnO2 (=382 K). These results suggest that Fe and Sn are a weakly bound lattice in goethite NPs with low crystallinity. Modification of NPs and addition of Sn has a positive effect, resulting in an increase in DC conductivity of almost 5 orders of magnitude, from a σDC value of 9.37 × 10−7 (Ω cm)−1 for pure goethite Sn (Sn0) up to DC plateau for samples containing 0.15 and 0.20 Sn (Sn15 and Sn20) with a DC value of ~4 × 10−7 (Ω cm)−1 @423 K. This non-linear conductivity pattern and levelling at a higher Sn content suggests that structural modifications have a notable impact on electron transport, which is primarily governed by the thermally activated via three-dimensional hopping of small polarons (SPH). Measurements of SIB performance, including the Sn100x cathode under a current density of 50 mA g−1, showed initial capacities of 81 and 85 mAh g−1 for Sn0 and Sn15, which were larger than the others. The large initial capacities were measured at a current density of 5 mA g−1 found at 170 and 182 mAh g−1 for Sn15 and Sn20, respectively. It is concluded that tin-goethite NPs are an excellent material for a secondary battery cathode and that Sn15 is the best cathode among the studied Sn100x NPs. LA - English DB - MTMT ER - TY - JOUR AU - Gracheva, Maria AU - Klencsár, Zoltán AU - Homonnay, Zoltán AU - Solti, Ádám AU - Péter, László AU - Machala, L. AU - Novak, P. AU - Kovács, Krisztina TI - Revealing the nuclearity of iron citrate complexes at biologically relevant conditions JF - BIOMETALS J2 - BIOMETALS PY - 2024 SN - 0966-0844 DO - 10.1007/s10534-023-00562-1 UR - https://m2.mtmt.hu/api/publication/34538304 ID - 34538304 LA - English DB - MTMT ER - TY - JOUR AU - Alenkina, Irina V. AU - Chukin, Andrey V. AU - Leitus, Gregory AU - Denisova, Olga V. AU - Gracheva, Maria AU - Felner, Israel AU - Kuzmann, Ernő AU - Homonnay, Zoltán AU - Oshtrakh, Michael I. TI - ANALYSIS OF THE IRON STATES IN IRON-CONTAINING PHARMACEUTICAL PRODUCTS USING MÖSSBAUER SPECTROSCOPY JF - JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS J2 - J PHARMACEUT BIOMED ANAL VL - 237 PY - 2024 SN - 0731-7085 DO - 10.1016/j.jpba.2023.115745 UR - https://m2.mtmt.hu/api/publication/34160976 ID - 34160976 N1 - Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002, Russian Federation Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel Laboratory of Nuclear Chemistry, Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary Hevesy Gyorgy Doctoral School of Chemistry, Eötvös Loránd University, Budapest, Hungary Racah Institute of Physics, The Hebrew University, Jerusalem, 91904, Israel Export Date: 16 November 2023 CODEN: JPBAD Correspondence Address: Oshtrakh, M.I.; Institute of Physics and Technology, Russian Federation; email: oshtrakh@gmail.com LA - English DB - MTMT ER - TY - JOUR AU - Oshtrakh, Michael I. AU - Alenkina, Irina V. AU - Chukin, Andrey V. AU - Kuzmann, Ernő AU - Homonnay, Zoltán TI - Comparison of two pharmaceutical products containing ferrous sulfate using Mössbauer spectroscopy JF - HYPERFINE INTERACTIONS J2 - HYPERFINE INTERACT VL - 244 PY - 2023 IS - 1 SN - 0304-3843 DO - 10.1007/s10751-023-01835-4 UR - https://m2.mtmt.hu/api/publication/34323900 ID - 34323900 LA - English DB - MTMT ER - TY - JOUR AU - Oshtrakh, Michael I. AU - Kuzmann, Ernő AU - Homonnay, Zoltán AU - Semionkin, Vladimir A. TI - Analysis of the differential nonlinearity for the velocity driving systems in Mössbauer spectrometers using thin α-Fe reference absorber JF - HYPERFINE INTERACTIONS J2 - HYPERFINE INTERACT VL - 244 PY - 2023 IS - 1 SN - 0304-3843 DO - 10.1007/s10751-023-01831-8 UR - https://m2.mtmt.hu/api/publication/34266835 ID - 34266835 LA - English DB - MTMT ER - TY - JOUR AU - Ibrahim, Ahmed AU - Watanabe, Satoshi AU - Razum, Marta AU - Pavić, Luka AU - Homonnay, Zoltán AU - Kuzmann, Ernő AU - Hassaan, Mohamed Yousry AU - Kubuki, Shiro TI - Structural, Electrical, and Electrochemical Properties of a Na2O-V2O5 Ceramic Nanocomposite as an Active Cathode Material for a Na-Ion Battery JF - CRYSTALS J2 - CRYSTALS VL - 13 PY - 2023 IS - 10 SN - 2073-4352 DO - 10.3390/cryst13101521 UR - https://m2.mtmt.hu/api/publication/34213280 ID - 34213280 AB - In this paper, a relationship between the structure and the electrical properties of a nanocrystalline composite ceramics xNa2O·(100 − x)V2O5 with ‘x’ of 5, 15, 25, 35, and 45 mol%, abbreviated as xNV, was investigated by X-ray diffractometry (XRD), X-ray absorption spectroscopy (XAS), Cyclic Voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and cathode active performance in Na-ion battery (SIB). For the expected sodium vanadium bronzes (NaxV2O5) precipitation, the preparation of xNV was performed by keeping the system in the molten state at 1200 °C for one hour, followed by a temperature decrease in the electric furnace to room temperature at a cooling rate of 10 °C min−1. XRD patterns of the 15NV ceramic exhibited the formation of Na0.33V2O5 and NaV3O8 crystalline phases. Moreover, the V K-edge XANES showed that the absorption edge energy of ceramics 15NV recorded at 5479 eV is smaller than that of V2O5 at 5481 eV, evidently indicating a partial reduction from V5+ to V4+ due to the precipitation of Na0.33V2O5. In the cyclic voltammetry, reduction peaks of 15NV were observed at 1.12, 1.78 V, and 2.69 V, while the oxidation peak showed up only at 2.36 V. The values of the reduction peaks were related to the NaV3O8 crystalline phase. Moreover, the diffusion coefficient of Na+ (DNa+) gradually decreased from 8.28 × 10−11 cm2 s−1 to 1.23 × 10−12 cm2 s−1 with increasing Na2O content (x) from 5 to 45 mol%. In the evaluation of the active cathode performance of xNV in SIB, ceramics 15NV showed the highest discharge capacity 203 mAh g−1 at a current rate of 50 mA g−1. In the wider voltage range from 0.8 to 3.6 V, the capacity retention was maintained at 50% after 30 cycles, while it was significantly improved to 90% in the narrower voltage range from 1.8 to 4.0 V, although the initial capacity decreased to 56 mAh g−1. It is concluded that the precipitation of the Na0.33V2O5 phase improved the structural and electrical properties of 15NV, which provides a high capacity for the Na-ion battery when incorporated as a cathode active material. LA - English DB - MTMT ER - TY - JOUR AU - Goryunov, M. V. AU - Varga, G. AU - Dankházi, Zoltán AU - Felner, I. AU - Chukin, A. V. AU - Kuzmann, Ernő AU - Homonnay, Zoltán AU - Grokhovsky, V. I. AU - Oshtrakh, M. I. TI - STUDY OF GIBEON IVA IRON METEORITE BY SCANNING ELECTRON MICROSCOPY, X-RAY DIFFRACTION, MAGNETIZATION MEASUREMENTS AND MOSSBAUER SPECTROSCOPY JF - METEORITICS & PLANETARY SCIENCE J2 - METEORIT PLANET SCI VL - 58 PY - 2023 IS - 1 SP - A108 EP - A108 PG - 1 SN - 1086-9379 UR - https://m2.mtmt.hu/api/publication/34194400 ID - 34194400 LA - English DB - MTMT ER -