In this work, a novel acidic catalyst based on protic ionic liquid (1-metylimidazoluim triflate, [Hmim][OTf]) and ZnO was developed. First, analysis of the structure was developed by HRMS, FT-IR and Raman spectroscopy, NMR, and X-ray absorption spectroscopy. The obtained results revealed an alternative structure and mechanism of the formation of the ionic liquid/ZnO adduct ([Hmim][OTf])3Zn. The developed liquid system was created based on the molar ratio of ([Hmim][OTf])3Zn and was shown as an effective acidic catalyst and solvent in the alternative synthesis of plasticizers. In particular, ([Hmim][OTf])3Zn (10mol%) displayed catalytic efficiency for the esterification of succinic acid, adipic acid, and lactic acid with two alcohols 1-butanol and 2-etylhexanol. For 2-ethyl-1-hexanol, full conversion of succinic acid was achieved after 1h at 130 °C. The synergistic effect of the ionic liquid and ZnO was demonstrated by comparing the catalytic efficiency of the individual components. ([Hmim][OTf])3Zn was used in six consecutive reaction cycles without a significant decrease in catalytic efficiency. Additionally, structural studies provided the foundation for the rational design and development of an acidic catalyst, consequently leading to a more environmentally friendly and economically feasible process.

ABS T R A C T The effects of degradation and possible leaching of lithium in the natural conditions were tested by subjecting LiMn2O4 to 3-month degradation in an open air environment. The starting material was characterized structurally using X-ray (XRD) and neutron (NPD) powder diffraction and found to crystallize in the nominal Fd-3m space group. The initial chemical composition was verified using X-ray photoelectron spectroscopy (XPS), electron microscopy (EDS) and neutron prompt gamma activation analysis (PGAA). The effects of degradation were studied by reinvestigating the samples using XRD, XPS and X-ray absorption (XAS). The studies did not find any chemical shift of manganese caused by the removal of Li or any statistically significant degradation of the starting composition suggesting that the spinel cathode material is resistant to possible Li removal due to medium term natural exposure.

We report on the investigation of magnetic and structural properties of AlCoCrCuFeNi, which is known to crystallize in a dual phase solid solution: the face-centred cubic (FCC) or the body-centred cubic (BCC). The results of neutron (NPD) and synchrotron powder diffraction (SXRD) allow to partially resolve magnetic information coming from BCC and FCC phases, which is impossible in the bulk magnetic measurements. Electron diffraction (PED) revealed that AlCoCrCuFeNi forms dendritic microstructure with the Cu-rich FCC phase and the Ni-rich BCC phase. Lattice parameters obtained from PED method are in good agreement with parameters obtained after refinement on the basis of powder X-ray diffraction measurements. The local crystal and electronic structure around Co was studied using Co K X-ray Absorption Spectroscopy (XAS). The magnetic measurements show that AlCoCrCuFeNi reveal a ferromagnetic transition at about 330 K and displays magnetic hysteresis loop at the room temperature. Results from NPD suggest that the magnetic moment is mostly located in the BCC subsystem. The alloy shows soft magnetic properties. Saturated magnetizations (Ms), remanence ratio (Mr/Ms) and coercivity (Hc) of the cast are estimated to be 45.10 emu/g, 5.1% and 56 Oe at 300 K, respectively. Finally, the BCC-FCC phase transformation up to 673 K (400 °C) was investigated using temperature dependent NPD, where a possible second BCC phase was identified.

In this research, we focused on studies of the influence of Cu addition on the structure and magnetic properties of FeCu-alloyed and Fe/Cu-multilayered nanowires electrodeposited into polycarbonate membranes. It was observed that Cu addition prevents oxidation of overdeposited caps, compared to the surface of membranes filled with pure Fe, which immediately becomes covered with an oxide layer in the air. TEM studies revealed the polycrystalline structure of the multilayered NWs and confirmed that the wires were composed of alternating Fe and Cu layers. Magnetic studies performed using a SQUID magnetometer indicated a magnetic anisotropy with an easy axis along the nanowires. The increase in the Cu concentration in alloyed nanowires from 10% to 30%, resulted in an increase in both coercivity and squareness by about 30%. In the case of multilayered nanowires, significant reduction in squareness and non-monotonic changes in coercivity with the increase in Cu layer thickness were observed.

One of the most common anticancer therapies is photothermal therapy (PTT). The effectiveness of PTT depends on the photosensitizer being a molecule which is toxic for the cancer cells after electromagnetic wave irradiation. Therefore, a simulation of PTT was performed in this work on two colon cancer cells (SW480 and SW620) using platinum nanoparticles (Pt NPs). Interestingly, in the literature the dependence between the synthesis method and the photothermal properties of Pt NPs was not discussed. Consequently, in this paper, we evaluated the photothermal properties of Pt NPs synthesized by two different methods: polyol (PtI NPs) and green chemistry (PtII NPs). Scanning transmission electron microscopy revealed that the size of both Pt NPs obtained was 2 nm, the NPs were not agglomerated, and that the PtII NPs were distributed on green tea supports. The selected area electron diffraction and X-ray diffraction analysis confirmed the crystallinity of both types of Pt NPs. Fourier-transform infrared (FTIR) spectrum of the PtII NPs showed interactions between the NPs and stretching modes for C=O groups from flavonoids and polyphenols. Therefore, these chemical compounds could be responsible for reducing Pt4+ ions to Pt-0. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay showed that the PtII NPs exhibited 10% and 20% better cytotoxicity effect on SW480 and SW620 cells, than PtI NPs. The viability of cancer cells decreased when Pt NPs were used in PTT. The highest percentage of dead cells (82%) was observed for PtII NPs and 650-nm laser irradiation. FTIR and Raman spectroscopy showed structural changes induced by both Pt NPs and laser irradiation of cells in the range corresponding to levels of DNA, phospholipids, proteins, and lipids. Moreover, the calculated photothermal conversion efficiency showed that the value of this parameter is around 35%, regardless of the synthesis method and used wavelengths.

An easy synthesis method of hollow, porous gold nanoparticles (AuHP NPs) with controlled diameter and pores sizes and with a wide range of light absorbance (continuous between 500 and 900 nm) is presented together with the explanation of the nanoparticle formation mechanism. The NPs were investigated using transmission electron microscopy (TEM) combined with the selected area electron diffraction patterns, X-ray diffraction and ultraviolet–visible spectroscopy. TEM images showed that changing the synthesis temperature allows to obtain AuHP NPs with sizes from 35 ± 4 nm at 60 °C to 76 ± 8 nm at 90 °C. The effects of nanoscale porosity on the far- and near-field optical properties of the nanoparticles, as well as on effective conversion of electromagnetic energy into thermal energy, were applied in simulated photothermal cancer therapy. The latter one was simulated by irradiation of two cancer cell lines SW480 and SW620 with lasers operating at 650 nm and 808 nm wavelengths. The mortality of cells after using the synthesized AuHP NPs as photosensitizers is between 20 and 50% and increases with the decrease in the diameter of the AuHP NPs. All these attractive properties of the AuHP NPs make them find application in many biomedical studies.

Photothermal therapy is a minimally invasive anticancer therapy, where the energy of light irradiation is converted by photothermal agents to heat energy, thus increasing the temperature in the cancer cells. The efficiency of this therapy depends on the used photosensitizer, which must have several design criteria, such as plasmon resonance tenability and conversion efficiency. Based on these criteria, gold nanodahlias (AuD NPs) were synthesized and their anticancer properties were determined under irradiation with lasers operating at three different electromagnetic wavelengths (405 nm, 650 nm and 808 nm) of two colon cancer cell lines SW480 and SW620. Scanning and transmission electron microscopies revealed that the size of the synthesized AuD NPs is around 70 nm, while their UV–Vis spectrum showed a maximum absorbance value at 625 nm wavelength. The MTS assay showed that for 625 nm laser irradiation in the presence of NPs, the mortality of the two lines of cancer cells is around 70%, in comparison with control samples (untreated cancer cells). Fourier-transform infrared and Raman spectroscopy showed that the most visible chemical changes, especially in DNA, RNA, phospholipids, lipids and proteins functional groups, occur in the colon cancer cells cultured with AuD NPs irradiated with 650 nm and 808 nm lasers. A photothermal conversion efficiency reaching 50% is observed for AuD NPs irradiated with 650 nm and 808 nm wavelengths. All of these properties of AuD NPs suggest that these nanoparticles could be effective potential nanophotosensitizers in photothermal anticancer therapy.

The patterning of the CoPd films was performed by the deposition of the Co/Pd multilayers on the nanoperforated templates of anodic aluminum oxide (AAO). We observed that the morphology of aluminum oxide is represented by the hexagonal packed hemispherical wells with a pore in the middle. The morphology of the patterned films follows the features of the initial templates; the magnetic material is deposited mainly in the regions between the pores and on their perimeter. The Co atoms diffuse into the Pd layer already during the film deposition, and discontinuous interfaces of Co and Pd are formed leading to the creation of the CoPd solid solution. The out-of-plane hysteresis loops of the nanoporous films exhibited high values of the coercive field (H-C = 2.0-3.6 kOe) and squareness ratio (Mr/M-s = 0.7-0.8). This indicates that the nanoporous films retain the perpendicular magnetic anisotropy observed for continuous film. Deteriorated values of effective anisotropy constant K-eff for the porous films with respect to the continuous film are explained by the complex morphology of the nanoporous films, which leads to partial deviation of magnetic moments from the direction normal to the sample plane. On the other hand the increase of the values of the coercive field H-C of the nanoporous films in comparison to the continuous films is related to the pinning of the magnetic moments on the nanopores. We observed the transition of the magnetization reversal mechanism from the domain wall motion observed for the continuous film, to coherent rotation mode for the nanoporous films. We show that this approach allows us to tune the coercive field and the effective magnetic anisotropy constant K-eff of the CoPd film by engineering the pore size of the templates.

Platinum nanoparticles (Pt NPs) with properties including damage of DNA, enzmatic activity and possibility of light absorption in the biological range could find application as effective photosensitizers in photothermal anticancer therapy (PTT). The photothermal properties of Pt NPs depend on their shape, size and crystalline structure. Therefore, in this paper the effect of Pt NPs size on photothermal efficiency is determined. For this purpose, spherical, crystalline 80 nm PtI NPs and 2 nm PtII NPs were synthesized and characterized by transmission electron microscopy (TEM), selected area diffraction patterns (SAED) and X-ray diffraction (XRD). The possibilities of using Pt NPs in PTT were investigated using two colon cancer cell lines: SW480 and SW620, which were cultured with both Pt NPs and irradiated by two, 650 nm and 808 nm lasers. Microscopy images of cells and MTS assay showed, that the PTT is the most effective when 2 nm nanoparticles and the 650 nm laser were used. The mortality of cells was around 62% for SW480 and 70% for SW620. Furthermore, higher temperatures after irradiation of Pt NPs by lasers were observed for the 2 nm Pt NPs for both wavelengths. Consequently, the values of photothermal efficiency are higher by approximately 5% and 6% for 2 nm Pt NPs, than for 80 nm ones, which were irradiated by 650 and 808 nm lasers, respectively. Moreover, the results obtained from experimental data corresponded with Mie theory.

An optical strain sensor was developed for use in stretchable electronics. It consists of a diffraction grating formed directly on the examined surface illuminated by a laser beam which creates interference pattern. This pattern can then be used to determine axial and lateral strains for a uniaxial stress states. Direct laser interference patterning was employed as a fast processing tool for the preparation of micro- and sub-microgratings. Two coherent beams of Nd:YAG laser with 532 nm wavelength and pulse duration of 10 ns were used to selectively remove material from the irradiated sample surface. This technique creates periodic pattern on the metallized surface of polymeric substrates. New sensors formed by direct laser interference patterning method were able to resolve higher order diffraction maxima, which would be of benefit for strain measurement application. Experimental setup for tensile tests was composed of laser probe, the sensor element, and CCD camera. To extract strain values, we analysed acquired interference pattern images in real time software, developed with LabVIEW environment. This kind of contactless strain sensor is suitable for examination of stretchable electronics component for which conventional tensile tests are either not acceptable or can interfere with its normal operation.

We studied changes of morphology and magnetic properties of Co/Cu multilayered nanowires, electrodeposited in polycarbonate membranes, as a function of Cu layer thickness. The morphology and structure of wire assemblies with an average diameter of 200 nm and length of 10 mu m, investigated by X-ray diffraction and scanning electron microscopy techniques, revealed polycrystalline structure of Cu and Co layers with smooth lateral surface of nanowires. Overdeposited nanowires created caps which showed flower-like dendrites with shape changing as a function of Cu thickness and electrodeposition parameters. Chemical composition of Co and Cu nanowires analysed by energy dispersive spectroscopy and proton induced X-ray emission showed Cu nanowires free from Co atoms while in Co nanowires, Cu contamination with concentration below 10% was observed. The oxidation traces observed in single-component Cu nanowires did not appear in multilayered nanowires. Magnetic measurements indicated easy axis of magnetization in membrane plane for nanowires with Cu thickness smaller than 20 nm, whereas for larger Cu thicknesses isotropic orientation of magnetization was observed. The presence of Cu atoms in single-component Co nanowires resulted in the appearance of magnetic anisotropy with easy axis along nanowire axis and the increase of coercivity value.

Physics, Chemistry and Application of Nanostructures, pp. 390-393 (2017) No AccessMORPHOLOGY OF ANODIC POROUS ALUMINA MEMBRANES FABRICATED ON SUBSTRATES WITH DIFFERENT ELECTRIC CONDUCTIVITYA. Maximenko, M. Marszałek, Y. Zabila and A. ZarzyckiA. MaximenkoInstitute of Nuclear Physics Polish Academy of Sciences Radzikowskiego Str. 152, PL 31-342 Krakow, PolandResearch Institute for Nuclear Problems of Belarusian State University Bobruiskaya 11, 220030 Minsk, Belarus, M. MarszałekInstitute of Nuclear Physics Polish Academy of Sciences Radzikowskiego Str. 152, PL 31-342 Krakow, Poland, Y. ZabilaInstitute of Nuclear Physics Polish Academy of Sciences Radzikowskiego Str. 152, PL 31-342 Krakow, Poland and A. ZarzyckiInstitute of Nuclear Physics Polish Academy of Sciences Radzikowskiego Str. 152, PL 31-342 Krakow, Polandhttps://doi.org/10.1142/9789813224537_0090Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: This work presents variations of morphology of porous anodic aluminum oxide (AAO) membranes prepared by anodization of Al foil and Al films deposited on semiconducting or dielectric substrates working as an additional electrical junction between anode and the anodized film. The pore diameter increases when electrical conductivity of the substrate increases. However, the cell diameter depends on electrolyte type and anodization voltage rather than on conductivity of the substrate. FiguresReferencesRelatedDetails Physics, Chemistry and Application of NanostructuresMetrics History PDF download

We used porous nanotubular templates of TiO2 for fabrication of Co/Pd antidot arrays with strong perpendicular magnetic anisotropy. The morphology of porous multilayers followed the features of the initial template demonstrating a pronounced relief consisting of the cells with periodic pores with small inclination. We confirmed the formation of Co0.4Pd0.6 alloy at the Co/Pd interface. We observed the conservation of perpendicular magnetic anisotropy in the Co/Pd porous film with coercive field H-C = 2.7 kOe, enhanced with respect to the continuous film due to the pinning of magnetic moments on the nanopore edges. From angular dependence of the coercive field HC we deduced the change of the magnetization reversal mechanism from domain wall motion in the continuous film to the predominantly coherent rotation mechanism in the porous film. (C) 2017 Elsevier B.V. All rights reserved.

For the first time, nanoporous Al2O3 templates with smoothed surface relief characterized by flattened interpore areas were used in the fabrication of Co/Pd and Co/Pt multilayers (MLs) with strong perpendicular magnetic anisotropy (PMA). Alternating gradient magnetometry (AGM) revealed perfectly conserved PMA in the Co/Pd and Co/Pt porous MLs (antidot arrays) with a ratio of remanent magnetization (M-r) to saturation magnetization (M-S) of about 0.99, anisotropy fields (H-a) of up to 2.6 kOe, and a small deviation angle of 8 degrees between the easy magnetization axis and the normal to the film surface. The sufficient magnetic hardening of the porous MLs with enhanced coercive field H-C of up to similar to 1.9 kOe for Co/Pd and similar to 1.5 kOe for Co/Pt MLs, as compared to the continuous reference samples (similar to 1.5-2 times), is associated with the pinning of the magnetic moments on the nanopore edges. Application of the Stoner-Wohlfarth model for fitting the experimental M/M-S(H) curves yielded clear evidence of the predominantly coherent rotation mechanism of magnetization reversal in the porous films. (C) 2017 Elsevier B.V. All rights reserved.

In this work, we propose a new method for the large-scale production of flexible, periodic alumina arrays with well-ordered pores. We show the incorporation of pre-patterning based on polystyrene (PS) nanosphere lithography into an aluminium anodization process. We prepared ordered monolayers of PS spheres with average diameters of (510 ± 10) nm and (430 ± 10) nm on a large area (1.5 × 1.5 cm2) of the Si substrate. Next, we deposited a 5 μm aluminium layer on arrays of PS nanospheres using the sputtering technique. After the deposition, we covered the aluminium film with a polymer Scotch adhesive tape, and separated it from the silicon substrate by ultrasonic-assisted lift-off. Finally, we performed the anodization of the aluminium. We compared the pore and cell sizes, and the pore distance for the templates obtained by this technique, with reference to the templates prepared by a two-step anodization process. Using this new approach, we obtained highly ordered hexagonal 2D lattices over a large area of up to 2 cm2 with sparse defects, amounting to not more than four defects per 1000 μm2 on average. Here, we show that the use of indentation techniques is not necessary and can be replaced by a fast, cheap and easy pre-patterning step based on nanosphere lithography.

Hard magnetic antidot arrays show promising results in context of designing of percolated perpendicular media. In this work the technology of magnetic FePd and CoPd antidot arrays fabrication is presented and correlation between surface morphology, structure and magnetic properties is discussed.CoPd and FePd antidot arrays were fabricated by deposition of Co/Pd and Fe/Pd multilayers (MLs) on porous anodic aluminum oxide templates with bowl-shape cell structure with inclined intercellular regions. FePd ordered L1(0) structure was obtained by successive vacuum annealing at elevated temperatures (530 degrees C) and confirmed by XRD analysis. Systematic analysis of magnetization curves evidenced perpendicular magnetic anisotropy of CoPd antidot arrays, while FePd antidot arrays revealed isotropic magnetic anisotropy with increased out-of-plane magnetic contribution. MFM images of anti-dots showed more complicated contrast, with alternating magnetic dots oriented parallel and anti-parallel to tip magnetization moment. (C) 2015 Elsevier B.V. All rights reserved.

Physics, Chemistry and Applications of Nanostructures, pp. 350-353 (2015) No AccessANTIDOT ARRAYS OF FePd: MODIFICATION OF MAGNETIC PROPERTIES BY SUCCESSIVE ANNEALINGA. MAXIMENKO, J. FEDOTOVA, M. MARSZAŁEK, Y. ZABILA, A. ZARZYCKI, B.R. JANY, and F. KROKA. MAXIMENKOResearch Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str. 11, 220030 Minsk, Belarus, J. FEDOTOVAResearch Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str. 11, 220030 Minsk, Belarus, M. MARSZAŁEKThe Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Str. 152, 31-342 Krakow, Poland, Y. ZABILAThe Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Str. 152, 31-342 Krakow, Poland, A. ZARZYCKIThe Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego Str. 152, 31-342 Krakow, Poland, B.R. JANYInstytut Fizyki, Uniwersytet Jagielloński, Gronostajowa 3, PL-30387 Krakow, Polska, and F. KROKInstytut Fizyki, Uniwersytet Jagielloński, Gronostajowa 3, PL-30387 Krakow, Polskahttps://doi.org/10.1142/9789814696524_0085Cited by:1 (Source: Crossref) PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: Antidot arrays of FePd L10 alloy with high out-of-plane magnetization component have been fabricated by deposition of Fe/Pd multilayers on the anodic aluminum oxide templates and their successive annealing at temperatures 450 °C and 530 °C. X-ray diffractometry proved formation of L10 structure after sample annealing at 530 °C. Magnetometry, magnetic force microscopy and scanning electron microscopy reveal that the enhancement of out-of-plane magnetization component is associated with complex distribution of magnetic moments orientation in FePd films deposited on the templates with a developed surface topography. FiguresReferencesRelatedDetailsCited By 1Cited by lists all citing articles based on Crossref citation.Magnetic properties of Co/Pd multilayered films on porous Al2O3 templates with developed cell substructureA. A. Maximenko, J. V. Kasiuk, J. A. Fedotova, M. Marszałek and Y. Zabila et al.20 September 2017 | Physics of the Solid State, Vol. 59, No. 9 Recommended Physics, Chemistry and Applications of Nanostructures Metrics History PDF download

Two granular systems (I and II) corresponding to oxide nanopowders having different agglomeration tendency are simulated by the granular dynamics method. The particle size is 10 nm. The interaction of particles involves the elastic forces of repulsion, the tangential forces of “friction”, the dispersion forces of attraction, and in the case of II system the opportunity of creation/destruction of hard bonds of chemical nature. The processes of the uniaxial compaction, the biaxial (radial) one, the isotropic one, the compaction combined with shear deformation as well as the pure shear deformation are studied. The effect of the positive dilatancy is revealed in the processes of shear deformation. The yield surfaces of nanopowders are constructed in the space of stress tensor invariants, i.e., the hydrostatic pressure and the deviator intensity. It is revealed that the form of the yield surfaces is similar to an ellipse, which is shifted along the hydrostatic axis to compressive pressures. The associated flow rule is analyzed. The nonorthogonality of the deformation vectors to the yield surface is established in both systems modeled.

Physics, Chemistry and Applications of Nanostructures, pp. 132-135 (2015) No AccessCoPd ANTIDOT ARRAYS WITH PERPENDICULAR MAGNETIC ANISOTROPY FABRICATED ON TiO2/Si TEMPLATESA. MAXIMENKO, J. FEDOTOVA, M. MARSZAŁEK, O. KUPREEVA and S. ZAVADSKIA. MAXIMENKOResearch Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str. 11, 220030 Minsk, Belarus, J. FEDOTOVAResearch Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str. 11, 220030 Minsk, Belarus, M. MARSZAŁEKThe Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences Radzikowskiego Str. 152, 31-342 Krakow, Poland, O. KUPREEVABelarusian State University of Informatics and Radioelectronics, P. Browka Str. 6, 220013 Minsk, Belarus and S. ZAVADSKIBelarusian State University of Informatics and Radioelectronics, P. Browka Str. 6, 220013 Minsk, Belarushttps://doi.org/10.1142/9789814696524_0034Cited by:2 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: For the first time CoPd antidot arrays are fabricated by deposition of CoPd multilayered films on nanoporous TiO2 grown on Si wafers. Systematic analysis of magnetization curves M(H) evidences conservation of perpendicular magnetic anisotropy and enhancement of coercive field HC associated with pinning of magnetic moments on nanopores. Magnetic characteristics of films are discussed with respect to the influence of flattened surface of TiO2 template on local misalignment of magnetic moments in the films. FiguresReferencesRelatedDetailsCited By 2Magnetic properties of Co/Pd multilayered films on porous Al2O3 templates with developed cell substructureA. A. Maximenko, J. V. Kasiuk, J. A. Fedotova, M. Marszałek and Y. Zabila et al.20 September 2017 | Physics of the Solid State, Vol. 59, No. 9Effect of the morphology on the mechanisms of the magnetization reversal of multilayered thin Co/Pd filmsJ. V. Kasiuk, A. A. Maksimenko, J. A. Fedotova, M. Marszałek and S. K. Lazaruk et al.15 November 2016 | Physics of the Solid State, Vol. 58, No. 11 Physics, Chemistry and Applications of NanostructuresMetrics History PDF download

This paper presents a numerical approach for modeling gravity-induced grain settling and shape distortion during liquid phase sintering of tungsten heavy alloys. Using the framework of the continuum theory of sintering, this formulation provides insight into the development of microstructure heterogeneities during sintering by including grain settling. The model contains information about the properties of the solid and liquid constituents to describe both low-temperature and high-temperature sintering. The kinetic equations for porosity and solid volume fraction are based on mass conservation. To demonstrate the capabilities of the constitutive formulation, finite element analysis is used to simulate densification, shape distortion and solid–liquid separation. The results are compared to data of liquid-phase sintering of cylindrical W–Ni–Fe samples. The developed model attempts to analyze the solid-skeletal dissolution and microstructure gradients that impact the system rigidity during liquid phase sintering.