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Effect of microwave heating during evaporation solvent and polymeric precursor formation in synthesis of BaZr0.08Ti0.92O3 nanopowders. J SOLID STATE CHEM 2020. [DOI: 10.1016/j.jssc.2020.121586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Miháliková I, Friák M, Koutná N, Holec D, Šob M. An Ab Initio Study of Vacancies in Disordered Magnetic Systems: A Case Study of Fe-Rich Fe-Al Phases. MATERIALS 2019; 12:ma12091430. [PMID: 31052537 PMCID: PMC6539047 DOI: 10.3390/ma12091430] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 04/25/2019] [Accepted: 04/28/2019] [Indexed: 11/16/2022]
Abstract
We have performed quantum-mechanical calculations to examine the impact of disorder on thermodynamic, structural and electronic (magnetic) properties of Fe-Al systems with vacancies. A series of supercells was used and their properties were computed employing density-functional theory (DFT) as implemented in the VASP package. Our case study is primarily aimed at a disordered solid solution Fe 81.25 Al 18.75 but we have compared our results also with those obtained for the ordered Fe 3 Al intermetallic compound for which experimental data exist in literature. Both phases are found in Fe-Al-based superalloys. The Fe-18.75at.%Al solid solution was simulated using special quasirandom structures (SQS) in three different disordered states with a different distribution of Al atoms. In particular, we have considered a general disordered case (an A2-like variant), the case without the first nearest neighbor Al-Al pairs (a B2-like distribution of atoms) and also the case without both the first and second nearest neighbor Al-Al pairs (the D0 3 -like variant, in fact, an Fe-rich Fe 3 Al phase). The vacancy formation energies as well as the volumes of (fully relaxed) supercells with vacancies showed a large scatter for the disordered systems. The vacancy formation energies decrease with increasing concentration of Al atoms in the first coordination shell around the vacancy (an anti-correlation) for all disordered cases studied. The computed volumes of vacancies were found significantly lower (by 25-60%) when compared with the equilibrium volume of the missing atoms in their elemental states. Lastly, we have analyzed interactions between the vacancies and the Fe atoms and evaluated vacancy-induced changes in local magnetic moments of Fe atoms.
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Affiliation(s)
- Ivana Miháliková
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
| | - Martin Friák
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
| | - Nikola Koutná
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Institute of Materials Science and Technology, TU Wien, Getreidemarkt 9, A-1060 Vienna, Austria.
| | - David Holec
- Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria.
| | - Mojmír Šob
- Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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Šesták P, Friák M, Holec D, Všianská M, Šob M. Strength and Brittleness of Interfaces in Fe-Al Superalloy Nanocomposites under Multiaxial Loading: An ab initio and Atomistic Study. NANOMATERIALS 2018; 8:nano8110873. [PMID: 30352963 PMCID: PMC6265909 DOI: 10.3390/nano8110873] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 10/18/2018] [Indexed: 11/21/2022]
Abstract
We present an ab initio and atomistic study of the stress-strain response and elastic stability of the ordered Fe3Al compound with the D03 structure and a disordered Fe-Al solid solution with 18.75 at.% Al as well as of a nanocomposite consisting of an equal molar amount of both phases under uniaxial loading along the [001] direction. The tensile tests were performed under complex conditions including the effect of the lateral stress on the tensile strength and temperature effect. By comparing the behavior of individual phases with that of the nanocomposite we find that the disordered Fe-Al phase represents the weakest point of the studied nanocomposite in terms of tensile loading. The cleavage plane of the whole nanocomposite is identical to that identified when loading is applied solely to the disordered Fe-Al phase. It also turns out that the mechanical stability is strongly affected by softening of elastic constants C′ and/or C66 and by corresponding elastic instabilities. Interestingly, we found that uniaxial straining of the ordered Fe3Al with the D03 structure leads almost to hydrostatic loading. Furthermore, increasing lateral stress linearly increases the tensile strength. This was also confirmed by molecular dynamics simulations employing Embedded Atom Method (EAM) potential. The molecular dynamics simulations also revealed that the thermal vibrations significantly decrease the tensile strength.
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Affiliation(s)
- Petr Šesták
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC BUT, Brno University of Technology, Purkyňova 123, CZ-612 00 Brno, Czech Republic.
| | - Martin Friák
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
| | - David Holec
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria.
| | - Monika Všianská
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
| | - Mojmír Šob
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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Kheradmandfard M, Kashani-Bozorg SF, Noori-Alfesharaki AH, Kharazi AZ, Kheradmandfard M, Abutalebi N. Ultra-fast, highly efficient and green synthesis of bioactive forsterite nanopowder via microwave irradiation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2018; 92:236-244. [PMID: 30184747 DOI: 10.1016/j.msec.2018.06.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 05/12/2018] [Accepted: 06/12/2018] [Indexed: 12/31/2022]
Abstract
Forsterite (Mg2SiO4) has recently attracted considerable attention in different fields because of its wide range of applications. In this paper, pure forsterite nanopowders were synthesized by an ultra-fast, highly efficient and green method for the first time. Microwave irradiation was used to synthesize forsterite nanopowder. The formation of highly crystalline forsterite nanopowder was confirmed by X-ray diffraction (XRD) and energy dispersive X-ray spectrometer (EDS) analyses. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed that the agglomerated powder composed of nanocrystalline particles with the mean particle size of ~100 nm. Microwave irradiation significantly accelerated the rate of the reactions and dramatically decreased reaction times from hours to minutes and seconds. In vitro bioactivity evaluation was performed by soaking the forsterite samples in simulated body fluid (SBF). Results indicated that synthesized forsterite nanopowder via microwave irradiation method possessed excellent apatite-forming ability in SBF. Cell viability results showed that synthesized forsterite nanopowder not only showed no cytotoxicity but also improved cell proliferation. Alkaline phosphatase (ALP) activity assay indicated that the fabricated forsterite nanopowder could facilitate the MG63 osteoblast-like cells to proliferate and differentiate. Therefore, microwave-assisted synthesis technique could be considered as a novel, safe and high efficient method in saving time and energy for bioactive forsterite nanopowder production.
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Affiliation(s)
- Mehdi Kheradmandfard
- School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran.
| | | | | | - Anoushe Zargar Kharazi
- Faculty of Biomaterials, Tissue Engineering and Nanotechnology, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Narges Abutalebi
- Biomaterials Research Group, Isfahan University of Medical Sciences, Isfahan, Iran
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Shekari M, Adeli M, Khobzi A, Kobashi M, Kanetake N. Induction-activated self-propagating, high-temperature synthesis of nickel aluminide. ADV POWDER TECHNOL 2017. [DOI: 10.1016/j.apt.2017.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Baykal A, Genç F, Elmal AZ, Gökçe S, Sertkol M, Sözeri H. MnCrxFe2−xO4 Nanoparticles: Magnetic and Microwave Absorption Properties. J Inorg Organomet Polym Mater 2015. [DOI: 10.1007/s10904-015-0288-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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