Search results

1

Determination of hyperfine fields and atomic ordering in NiMnFeGe exhibiting martensitic transformation

100%

Satuła D., Szymański K., Rećko K., Olszewski W., Kalska-Szostko B.

Nukleonika

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2015

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vol. 60

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issue 1

127-131

EN

The hyperfine fields and atomic ordering in Ni1−xFexMnGe (x = 0.1, 0.2, 0.3) alloys were investigated using X-ray diffraction and Mössbauer spectroscopy at room temperature. The X-ray diffraction measurements show that the samples with x = 0.2, 0.3 crystallized in the hexagonal Ni2In-type of structure, whereas in the sample with x = 0.1, the coexistence of two phases, Ni2In- and orthorhombic TiNiSi-type of structures, were found. The Mössbauer spectra measured with x = 0.2, 0.3 show three doublets with different values of isomer shift (IS) and quadrupole splitting (QS) related to three different local surroundings of Fe atoms in the hexagonal Ni2In-type structure. It was shown that Fe atoms in the hexagonal Ni2In-type structure of as-cast Ni1−xFexMnGe alloys are preferentially located in Ni sites and small amount of Fe is located in Mn and probably in Ge sites. The spectrum for x = 0.1 shows the doublets in the central part of spectrum and a broad sextet. The doublets originate from the Fe atoms in the paramagnetic state of hexagonal Ni2In-type structure, whereas the sextet results from the Fe atoms in orthorhombic TiNiSi-type structure.

2

The crystal structure of Sm4Ni11In20 and its relation to other indium-rich compounds

100%

Tyvanchuk Y., Svitlyk V., Pustovoychenko M., Kalychak Y.

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issue 2

227-232

EN

Polycrystalline Sm4Ni11In20 was obtained by arc-melting of metal ingots. A subsequent high temperature treatment was used for single crystal growth. The Sm4Ni11In20 crystal structure (U4Ni11Ga20 type; C2/m, a = 22.5457(3) Å, b = 4.34929(5) Å, c = 16.5479(2) Å, β = 124.592(2)°, R1 = 0.0358, wR2 = 0.0934) was determined by single crystal synchrotron radiation X-ray diffraction from 2014 independent reflections with I > 2σ(I). Sm4Ni11In20 extends the R 4Ni11In20 (R = Y, Gd, Tb, Dy, Ho) series of phases. The R 4Ni11In20 and RNi3In6 (LaNi3In6 type; R = La, Ce, Pr, Nd, Eu) series have similar compositions. Their structures share similar fragments; in particular the rare earth atom coordination polyhedra are pentagonal prisms with additional atoms.

3

X-ray diffraction and Mössbauer spectroscopy studies of a mechanosynthesized Fe75B25alloy

100%

Jartych E., Kubalova L. M., Fadeeva V. I.

Nukleonika

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2015

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vol. 60

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issue 1

43-46

EN

In this work, the process of formation of metastable phases was investigated for the Fe75B25 composition. Mechanical synthesis was performed in a MAPF-2M high-energy planetary ball mill under an argon atmosphere. X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Mössbauer spectroscopy (MS) were applied to recognize the phases. After 6 h of milling, the material consisted of two phases, that is, metastable tetragonal t-Fe2B and amorphous phases. During further thermal processing, the metastable phase was transformed into the stable Fe2B phase.

4

X-ray Diffraction Study of Directional Solidification Ledeburite

100%

Trepczyńska-Łent M., Szykowny T.

Archives of Foundry Engineering

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2015

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issue 3

5

X-Ray Diffraction Study of Bismuth Layer-Structured Multiferroic Ceramics

100%

Lisińska-Czekaj A., Czekaj D., Garbarz-Glos B., Bąk W., Kuźniarska-Biernacka I., Lisińska-Czekaj A., Czekaj D., Garbarz-Glos B., Bąk W., Kuźniarska-Biernacka I.

Archives of Metallurgy and Materials

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2020

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vol. 65

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issue 2

6

Dielectric properties of Ba3Sr2DyTi3V7O30 ceramics

100%

Sahoo P., Panigrahi A., Patri S., Choudhary R.

Open Physics

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2010

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vol. 8

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issue 4

639-642

EN

A polycrystalline sample, Ba3Sr2DyTi3V7O30, with tungsten bronze structure was prepared by a mixed-oxide method at high temperature (950°C). Preliminary structural analysis of the compound showed an orthorhombic crystal structure at room temperature. Surface morphology of the compound was studied by scanning electron microscopy. The dielectric anomaly at 321°C may be attributed to the ferro-paraelectric phase transitions. This was also confirmed from the appearance of a hysteresis loop. The nature of variation of the ac conductivity and value of activation energy at different temperature regions, suggest that the conduction process is of mixed-type (i.e., ionic-polaronic and space charge generated from the oxygen ion vacancies).

7

Influence of pH on the Structural and Optical Properties of Polycrystalline MnTe₂ Thin Films Produced by Chemical Bath Deposition Method

100%

Kariper İ., Göde F.

Acta Physica Polonica A

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2017

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vol. 132

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issue 3

531-534

EN

Polycrystalline manganese ditelluride (MnTe₂) thin films are synthesized on commercial glass substrates by chemical bath deposition technique at different pH values (pH = 9, 10, 11 and 12). The effect of pH on the structural and optical properties of chemically deposited MnTe₂ thin films have been investigated in this study. The structure and optical properties of the films are characterized by X-ray diffraction and optical absorption spectroscopy. The X-ray diffraction results suggest that the films are polycrystalline with a mixture of dominant cubic MnTe₂ phase and few traces of orthorhombic MnTeO₃ and MnTe₂O₅ phases. The optical band gap of the films increases approximately from 1.66 eV to 2.62 eV with increasing pH. Moreover, optical parameters of the films such as refractive index, extinction coefficient, real and imaginary dielectric constants are investigated using absorption and transmittance spectra taken from the UV-vis spectrophotometer. At 600 nm wavelength, refractive index and extinction coefficient values vary in the range of 1.39-1.55 and 0.17-0.23, respectively. An increase in optical band gap could be attributed to the quantum confinement effect.

8

Phase transition in Bi8Fe6Ti3O27 multiferroic ceramics

100%

Patri S., Choudhary R.

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vol. 6

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issue 3

450-453

EN

The polycrystalline Bi8Fe6Ti3O27 compound was prepared by a high-temperature solid-state reaction technique. Preliminary structural analysis by X-ray diffraction (XRD) confirms the formation of a single-phase compound in an orthorhombic crystal system at room temperature. The elemental content of the compound was analyzed by EDAX microanalysis. Microstructural analysis by scanning electron microscopy (SEM) shows that the compound has well defined grains, which are distributed uniformly throughout the surface of the pellet sample. Detailed studies of temperature-dependent dielectric response at various frequencies show dielectric anomalies at 380, 389 and 403°C for 10 kHz, 100 kHz, and 1 MHz respectively. The hysteresis loop observed by applying an electric field of 12 kV/cm on the poled sample with smaller remanent polarization supports the existence of ferroelectricity in this material. The value of d33 of the compound was found to be 19 pC/N.

9

Application of X-Ray Diffraction to Analyse Phase Composition of Aluminium Alloysfor Plastic Working

100%

Pachut K., Żelechowski J., Boczkal S., Pachut K., Żelechowski J., Boczkal S.

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issue 4

10

Doped Bi2Te3 nano-structured semiconductors obtained by ultrasonically assisted hydrothermal method

100%

Novaconi S., Vlazan P., Malaescu I., Badea I., Grozescu I., Sfirloaga P.

Open Chemistry

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2013

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vol. 11

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issue 10

1599-1605

EN

Nanocrystalline powders of doped Bi2Te3, with Ag (S1 sample), Sb (S2 sample), Sn (S3 sample) ions with different morphology and particle size 30–50 nm were prepared by a ultrasonically assisted hydrothermal method in alkaline aqueous solution with different concentration of NaBH4 as reducing agent at 200°C for 3 hours and 80% fill degree of autoclave. The influence of dopants and hydrothermal treatment conditions on the formation features, phase composition, particle size, morphology and properties of the products were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy and electrical measurements. This paper reports a comparative study regarding the dopants influence to the shape and size of nano-structured thermoelectric materials. It was found that hydrothermal processing results in formation of low dimensional dispersion of doped Bi2Te3 nanostructures with desired shape and size and high degree of crystallinity with typical semiconductor behavior. [...]

11

The crystal structure of Ho4Ni11In20

100%

Tyvanchuk Y., Svitlyk V., Kalychak Y.

Open Chemistry

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2012

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vol. 10

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issue 2

354-359

EN

The polycrystalline Ho4Ni11In20 was obtained by arc-melting of the elements. The subsequent high temperature procedure was used for single crystal growth. Crystal structure of the compound was investigated by X-ray single crystal method: U4Ni11Ga20 type, C 2/m, a = 22.4528(17), b = 4.2947(3), c = 16.5587(13) Å, β = 124.591(5)°, R1 = 0.0276, wR2 = 0.0493 for 1989 independent reflections with [I>2σ(I)]. The structure is composed of three-dimensional network from Ni and In atoms in which Ho atoms fill distorted pentagonal channels. [...]

12

The binary system PbO - BiVO4

88%

Bosacka M., Szkoda I.

Open Chemistry

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2009

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vol. 7

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issue 3

512-518

EN

Phase equilibria established in the PbO - BiVO4 system over the whole component concentration range up to 1000°C have been investigated. A phase diagram has been constructed using DTA and XRD. [...]

13

Hyperfine interaction and some thermomagnetic properties of amorphous and partially crystallized Fe70−xMxMo5Cr4Nb6B15(M = Co or Ni,x= 0 or 10) alloys

88%

Rzącki J., Świerczek J., Hasiak M., Olszewski J., Zbroszczyk J., Ciurzyńska W.

Nukleonika

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2015

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vol. 60

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issue 1

121-126

EN

As revealed by Mössbauer spectroscopy, replacement of 10 at.% of iron in the amorphous Fe70Mo5Cr4Nb6B15 alloy by cobalt or nickel has no effect on the magnetic structure in the vicinity of room temperature, although the Curie point moves from 190 K towards ambient one. In the early stages of crystallization, the paramagnetic crystalline Cr12Fe36Mo10 phase appears before α-Fe or α-FeCo are formed, as is confirmed by X-ray diffractometry and transmission electron microscopy. Creation of the crystalline Cr12Fe36Mo10 phase is accompanied by the amorphous ferromagnetic phase formation at the expense of amorphous paramagnetic one.

14

Controlled synthesis, characterization and thermal properties of Mg2B2O5

88%

Üçyıldız A., Girgin İ.

Open Chemistry

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2010

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vol. 8

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issue 4

758-765

EN

Optimum conditions for synthesizing monoclinic and triclinic Mg2B2O5 compounds by high-temperature solid-state reactions were investigated. Mixtures composed of boric acid and magnesium oxide at MgO:B2O3 mole ratios of 1:0.25, 1:0.5 and 1:1.5 were heated for 1 hour at temperatures between 600–1050°C and the formed phases were identified by XRD analysis. Monoclinic Mg2B2O5 was formed by heating at 850°C for 4 hours together with minimum amounts of triclinic Mg2B2O5, while triclinic Mg2B2O5 was formed as a single phase at 1050°C for the same reaction time. The products obtained at optimum conditions were subjected to a series of tests to determine their chemical compositions, particle size distributions, surface area values, IR spectra and TG/DTA patterns. [...]

15

Physical-chemical transformations in the system V2O5/(NH4)2Mo2O7 under hydrothermal conditions

88%

Khalameida S., Sydorchuk V., Leboda R., Skubiszewska-Zięba J., Zazhigalov V.

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issue 2

140-152

EN

Modified compositions in the system V2O5/(NH4)2Mo2O7 have been prepared by means of mechanochemical, hydrothermal, microwave and ultrasonic treatments in aqueous medium. Chemical and phase transformations occurring on the stages of modification and following calcinations have been studied with the help of XRD, DTA-TG, FTIR and UV-Vis spectroscopy, nitrogen adsorption, and SEM. It has been established that precursors of catalytically active phases possessing meso-macroporous structure have been formed during modification. The comparison of the properties of compositions prepared via different methods has been carried out. Particularly, precursors modified via various procedures possess different morphology.

16

Kinetics of nanocrystalline iron nitriding

88%

Arabczyk W., Zamłynny J., Moszyński D.

Polish Journal of Chemical Technology

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2010

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vol. 12

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issue 1

38-43

EN

Nitriding of nanocrystalline iron was studied under the atmosphere of pure ammonia and in the mixtures of ammonia - hydrogen - nitrogen at temperatures between 350°C and 500°C using thermogravimetry and x-ray diffraction. Three stages of nitriding were observed and have been ascribed to the following schematic reactions: (1) α-Fe → γ'-Fe4N, (2) γ'- Fe4N → ε - Fe3N and (3) ε - Fe3N → ε - Fe2N. The products of these reactions appeared in the nitrided nanocrystalline iron not sequentially but co-existed at certain reaction ranges. The dependence of a reaction rate for each nitriding stage on partial pressure of ammonia is linear. Moreover, a minimal ammonia partial pressure is required to initiate the nitriding at each stage.

17

The influence of the chelating/combustion agents on the structure and magnetic properties of zinc ferrite

88%

Slatineanu T., Diana E., Nica V., Oancea V., Caltun O., Iordan A., Palamaru M.

Open Chemistry

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2012

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vol. 10

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issue 6

1799-1807

EN

The present study is reporting the influence of the chelating/combustion agents on the magnetic properties of Zn ferrite. Six chelating/combustion agents, citric acid, egg white, tartaric acid, glycine, glucose and urea, were used to obtain monophase zinc nanoferrite via a sol-gel auto-combustion method. The samples were subjected to a comparative study of structural features and magnetic properties by means of infrared spectroscopy, X-ray diffractometry, scanning electron microscopy and vibrating sample magnetometry. Significant influence of fuel and combustion mode was observed in the magnetic behavior of as-obtained samples. Values of the structural parameters were discovered to vary as a function of fuel choice, and to obtain crystallite size between 38 and 62 nm, inversion degree between 0.239 and 0.807, lattice parameter between 8.4125 and 8.4432 Å. The optimization of sol-gel method synthesis of zinc ferrite nanoparticles by chosing the appropriate fuel is providing structural and magnetic properties of zinc nanoferrite as potential materials to be used in biomedical applications. [...]

18

XRD and EBSD Measurements of Directional Solidification Fe-C Eutectic Alloy

88%

Trepczyńska-Łent M.

Archives of Foundry Engineering

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2016

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issue 4

19

Structural, dielectric, electrical and piezoelectric properties of Ba4SrRTi3V7O30 (R=Sm, Dy) ceramics

88%

Sahoo P., Panigrahi A., Patri S., Choudhary R.

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vol. 6

|

issue 4

843-848

EN

Polycrystalline samples of Ba4SrRTi3V7O30 (R=Sm and Dy), members of the tungsten-bronze family, were prepared using a high-temperature, solid-state reaction technique and studied their electrical properties (using complex impedance spectroscopy) in a wide range of temperature (31–500°C) and frequency (1 kHz-1 MHz). Preliminary structural (XRD) analyses of these compounds show the formation of single-phase, orthorhombic structures at room temperature. The scanning electron micrographs (SEM) provided information on the quality of the samples and uniform distribution of grains over the entire surface of the samples. Detailed studies of the dielectric properties suggest that they have undergone ferroelectric-paraelectric phase transition well above the room temperatures (i.e., 432 and 355°C for R= Sm and Dy, respectively, at frequency 100 kHz). Measurements of electrical conductivity (ac and dc) as a function of temperature suggest that the compounds have semiconducting properties much above the room temperature, with negative temperature coefficient of resistance (NTCR) behavior. The existence of ferroelectricity in these compounds was confirmed from a polarization study.

20

L-alaninium perrhenate: crystal structure and non-linear optical properties

88%

Rodrigues V., Costa M., Gomes E., Isakov D., Belsley M.

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issue 10

1016-1022

EN

The crystal structure and non-linear optical properties of L-alaninium perrhenate, C3H8NO2+ ReO4 −, are reported. The protonated amino acid and the perrhenate anion have their usual geometries. The three-dimensional hydrogen-bonded network can be seen as a stacking of layers parallel to the (100) planes. Each layer is formed by chains of alternating positive and negative ions along the b and c axes. Hydrogen bonding of adjacent layers forms alternating chains along the a axis. A high damage threshold and a second-harmonic generation efficiency three times that of KDP make this new material potentially useful in non-linear optics.

Refine search results

Determination of hyperfine fields and atomic ordering in NiMnFeGe exhibiting martensitic transformation

The crystal structure of Sm4Ni11In20 and its relation to other indium-rich compounds

X-ray diffraction and Mössbauer spectroscopy studies of a mechanosynthesized Fe75B25alloy

X-ray Diffraction Study of Directional Solidification Ledeburite

X-Ray Diffraction Study of Bismuth Layer-Structured Multiferroic Ceramics

Dielectric properties of Ba3Sr2DyTi3V7O30 ceramics

Influence of pH on the Structural and Optical Properties of Polycrystalline MnTe₂ Thin Films Produced by Chemical Bath Deposition Method

Phase transition in Bi8Fe6Ti3O27 multiferroic ceramics

Application of X-Ray Diffraction to Analyse Phase Composition of Aluminium Alloysfor Plastic Working

Doped Bi2Te3 nano-structured semiconductors obtained by ultrasonically assisted hydrothermal method

The crystal structure of Ho4Ni11In20

The binary system PbO - BiVO4

Hyperfine interaction and some thermomagnetic properties of amorphous and partially crystallized Fe70−xMxMo5Cr4Nb6B15(M = Co or Ni,x= 0 or 10) alloys

Controlled synthesis, characterization and thermal properties of Mg2B2O5

Physical-chemical transformations in the system V2O5/(NH4)2Mo2O7 under hydrothermal conditions

Kinetics of nanocrystalline iron nitriding

The influence of the chelating/combustion agents on the structure and magnetic properties of zinc ferrite

XRD and EBSD Measurements of Directional Solidification Fe-C Eutectic Alloy

Structural, dielectric, electrical and piezoelectric properties of Ba4SrRTi3V7O30 (R=Sm, Dy) ceramics

L-alaninium perrhenate: crystal structure and non-linear optical properties