Dielectric and Magnetoelectric Properties of Nano-Microscale Lead-Free Composite by 0.4Co-Ferrite and 0.6(K0.5Na0.5)NbO3-Based Ferroelectric Matrix

(y) Li0.5Ni0.7Zn0.05Fe2O4+ (1-y) Ba0.5Sr0.5TiO3magnetoelectric composites with y = 0.1, 0.3 and 0.5 were prepared by a conventional standard double sintering ceramic technique. X-ray diffraction analysis confirmed the phase formation of ferrite, ferroelectric and their composites. logρdcVs 1/T graphs reveal that the dc resistivity decreases with increasing temperature exhibiting semiconductor behavior. The plots of logσacVs logω2are almost linear indicating that the conductivity increases with increase in frequency i.e. conductivity in the composites is due to small poloron hopping. Dielectric constant (έ) and dielectric loss (tan δ) were studied as a function of frequency in the range 100Hz–1MHz which reveal the normal dielectric behavior except the composite with y = 0.1and as a function of temperature at four fixed frequencies (i.e. 100Hz, 1KHz, 10KHz, 100KHz). ME voltage coefficient decreases with increase in ferrite content and was observed to be maximum of about 7.495 mV/cmOe for S1i.e. (0.1) Li0.5Ni0.7Zn0.05Fe2O4+ (0.9) Ba0.5Sr0.5TiO3composite.

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Preparation, microstructure studies and mechanical properties of glazes ceramic sanitary ware based on kaolin

Science of Sintering ◽

10.2298/sos2102209b ◽

2021 ◽

Vol 53 (2) ◽

pp. 209-221

Author(s):

Samra Benkacem ◽

Kamel Boudeghdegh ◽

Fouzia Zehani ◽

Mohamed Hamidouche ◽

Youghourta Belhocine

Keyword(s):

Vickers Microhardness ◽

Sanitary Ware ◽

X Ray Diffraction ◽

Water Absorption Coefficient ◽

X Ray ◽

Glazed Ceramic ◽

Processing Techniques ◽

Very High ◽

Conventional Ceramic Processing ◽

Potential Use

In this paper, the use of local kaolin coming from Djebel Debbagh (denoted DD1) in the composition of ceramic glazes for sanitary ware was examined. Because of its natural abundance, low price and good characteristics, this kaolin represents an interesting economic alternative to other mineral clays. The chemical composition showed that this kaolin contains 38.49 wt.% Al2O3 and 44.85 wt.% SiO2. Two glazes based on kaolin DD1 denoted as GaDD1 and GbDD1 were prepared with conventional ceramic processing techniques at temperature 1250 oC. As a reference, another glaze (Gref) based on kaolin Remblend was also prepared in the same conditions. The samples were characterized with X-ray diffraction and Scanning Electron Microscope. The results revealed that zircon and quartz are the crystalline phases present in these glazes. In the sample GaDD1, it was found that the degree of whiteness is very high and reaches 93.30 %. However, the water absorption coefficient is low which is about 0.19 ? 0.04 %. In addition, the flexural strength and the Vickers microhardness are respectively, about 56.07 ? 5.61 MPa and 7952.80 ? 101.76 MPa. These properties are compatible with those of the glaze reference Gref and commercial sanitary ware glazes, indicating the potential use of kaolin DD1 in the production of glazed ceramic for sanitary ware applications.

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Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173996 ◽

1990 ◽

Vol 48 (4) ◽

pp. 172-173

Author(s):

Naoki Yamamoto ◽

Makoto Kikuchi ◽

Tooru Atake ◽

Akihiro Hamano ◽

Yasutoshi Saito

Keyword(s):

Phase Transition ◽

Electron Microscope Study ◽

Room Temperature ◽

Hexagonal Lattice ◽

Ferroelectric Materials ◽

Temperature Phase ◽

X Ray Diffraction ◽

X Ray ◽

Periodic Arrays ◽

Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

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Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

10.26434/chemrxiv.9943961.v2 ◽

2019 ◽

Author(s):

Till Fuchs ◽

Sean Culver ◽

Paul Till ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Vacancy Concentration ◽

Sodium Ion ◽

High Ionic Conductivity ◽

Ionic Conductors ◽

X Ray Diffraction ◽

X Ray ◽

Solid State Batteries ◽

Ion Conducting ◽

Very High

The sodium-ion conducting family of Na3PnS4, with Pn = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na3PnS4, the solid solutions with WS42- introduction are explored. The influence of the substitution with WS42- for PS43- and SbS43-, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm-1 for Na2.9P0.9W0.1S4 and 41 ± 8 mS·cm-1 for Na2.9Sb0.9W0.1S4 can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.

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Defect-Mediated Conductivity Enhancements in Na3-xPn1-xWxS4 (Pn = P, Sb) using Aliovalent Substitutions

10.26434/chemrxiv.9943961.v1 ◽

2019 ◽

Author(s):

Till Fuchs ◽

Sean Culver ◽

Paul Till ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Vacancy Concentration ◽

Sodium Ion ◽

High Ionic Conductivity ◽

Ionic Conductors ◽

X Ray Diffraction ◽

X Ray ◽

Solid State Batteries ◽

Ion Conducting ◽

Very High

The sodium-ion conducting family of Na3PnS4, with Pn = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na3PnS4, the solid solutions with WS42- introduction are explored. The influence of the substitution with WS42- for PS43- and SbS43-, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm-1 for Na2.9P0.9W0.1S4 and 41 ± 8 mS·cm-1 for Na2.9Sb0.9W0.1S4 can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.

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Carbonaceous materials used in the production of aluminium. Calcined coke. Determination of crystallite size of calcined petroleum coke by X-ray diffraction

10.3403/30106379u ◽

2015 ◽

Keyword(s):

Crystallite Size ◽

Petroleum Coke ◽

Carbonaceous Materials ◽

X Ray Diffraction ◽

X Ray ◽

Calcined Petroleum Coke ◽

Materials Used

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Thermal analysis and X-ray diffraction of untreated coffee’s husk ash reject and its potential use in ceramics

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-012-2478-0 ◽

2012 ◽

Vol 111 (2) ◽

pp. 1331-1334 ◽

Cited By ~ 5

Author(s):

W. Acchar ◽

E. J. V. Dultra

Keyword(s):

Thermal Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Potential Use

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Early Palaeolithic bone diagenesis in the Arago cave at Tautavel, France

Mineralogical Magazine ◽

10.1180/002646199548943 ◽

1999 ◽

Vol 63 (6) ◽

pp. 801-812 ◽

Cited By ~ 27

Author(s):

L. Quattropani ◽

L. Charlet ◽

H. de Lumley ◽

M. Menu

Keyword(s):

Clay Minerals ◽

Gamma Ray ◽

Trace Element Composition ◽

Element Composition ◽

X Ray Diffraction ◽

Human Occupation ◽

X Ray ◽

Bone Diagenesis ◽

Very High ◽

P Influx

AbstractBones from level G in the Arago cave (Tautavel, Southern France, 450 ky) were analysed using a combination of particle induced X-ray and gamma-ray emission (PIXE and PIGME) and X-ray diffraction (XRD). Human occupation and guano production by bats introduced a large amount of phosphate into the cave and as a result a decarbonated pocket was formed in the sediment, characterized by the dissolution of clay minerals, calcite and bones, and by the precipitation of phosphate secondary minerals. The Al released by clay minerals was reprecipitated as crandallite in the few remaining bones, and as montgomeryite with traces of crandallite in the surrounding sediments. Bones within the pocket have very high levels of Al, Fe, F and Zn and often have ‘diffusive’ type U-shaped concentration profiles. These profiles show that post-mortem uptake of trace elements occurred, and thus that trace element composition has to be used with care in palaeonutritional studies but is indicative of local palaeoenvironment. This uptake is complicated by a large increase in hydroxylapatite crystallinity in Palaeolithic bones compared to modern or more recent ones, as a result of the large P influx which occurred in the Arago cave after the sediment deposition.

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Investigation of Magnetic Order in Iron Oxide-Nickel Oxide Superlattices with Modulation Wavelength Less Than 80 Å

MRS Proceedings ◽

10.1557/proc-231-423 ◽

1991 ◽

Vol 231 ◽

Author(s):

S. D. Berry ◽

D. M. Lind ◽

G. Chern ◽

H. Mathias ◽

L. R. Testardi

Keyword(s):

Magnetic Order ◽

Spontaneous Magnetization ◽

X Ray Diffraction ◽

High Crystalline Quality ◽

X Ray ◽

Long Wavelength ◽

Saturation Moment ◽

Very High ◽

Modulation Wavelength

AbstractWe have investigated the magnetic order, using SQUID magnetometry, for short modulation wavelength Fe3O4/NiO superlattices, grown on single crystal MgO. Ferrimagnetic Fe3O4 has a saturation moment of ~500 emu/cm3 at 0 K and a Curie temperature of 858 K, while bulk NiO is antiferromagnetic with a NMel temperature of 525 K. Very high crystalline quality with little interdiffusion is indicated by X-ray diffraction, SEM, optical microscopy, and in-situ RHEED, and the samples show highly anisotropic electrical conductivity which also indicates the strong modulation present. Long wavelength samples (Amod > 200 Å) have a behavior only slightly different from that expected from bulk Fe3O4, but for Amod<80 Å, spontaneous magnetization is replaced by paramagnetism, with weak temperature dependence (not I/T) from 5 K to 400 K.

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INFLUENCE OF INTERFACE AND POLARIZATION ON MAGNETOELECTRIC COUPLING IN Ni-LEAD ZIRCONIUM TITANATE-Ni TRILAYERS DERIVED BY ELECTROLESS DEPOSITION

Surface Review and Letters ◽

10.1142/s0218625x12500308 ◽

2012 ◽

Vol 19 (03) ◽

pp. 1250030

Author(s):

K. BI ◽

Y. G. WANG

Keyword(s):

Cross Section ◽

Electroless Deposition ◽

Mechanical Deformation ◽

Interface Roughness ◽

Zirconium Titanate ◽

Interface Conditions ◽

Lead Zirconium Titanate ◽

X Ray Diffraction ◽

X Ray ◽

Voltage Coefficient

Magnetoelectric (ME) coupling in layered structures of magnetostrictive and piezoelectric phases are mediated by mechanical deformation and depends strongly on the interface conditions. Ni -lead zirconium titanate- Ni trilayers with neither electrodes nor bonding layers have been derived by electroless deposition. The structure of the electroless deposited Ni layer was characterized by X-ray diffraction. The cross-section of the Ni/PZT layers was investigated using scanning electron microscopy. The value of ME voltage coefficient (αE,31) increases as the interface roughness increases. The maximum of αE,31 for the Ni/PZT/Ni trilayers polarized after electroless deposition is higher than that for the Ni/PZT/Ni trilayers polarized before electroless deposition. It is essential to optimize the interface and the polarization to obtain higher ME voltage coefficient.

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