scholarly journals X-Ray Powder Diffraction Study on the MgB2 Superconductor Reacted with Nano-SiC: The Effects of Sintering Temperature

2010 ◽  
Vol 173 ◽  
pp. 78-83
Author(s):  
Kwee Yong Tan ◽  
Tan Kim Lee ◽  
Lim Kean Pah ◽  
Shaari Abdul Halim ◽  
Tan Kar Ban ◽  
...  
Keyword(s):  
Phase Formation ◽  
Sintering Temperature ◽  
Lattice Parameter ◽  
Primary Phase ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Higher Temperature ◽  
Addition Level

SiC added MgB2 polycrystalline samples were synthesized at low (650°C) and high (850°C) temperatures in order to study the sintering effect on the phase formation and superconducting properties. The MgB2 bulks with additions of 0wt%, 1wt%, 3wt% and 5wt% SiC were studied with powder X-ray diffraction technique. We observed that MgB2 remained as the primary phase for both sintering temperatures in all samples with the presence of MgO and Mg2Si as the main impurities. Some diffraction peaks associated with unreacted SiC is also noticeable. The relative intensity of the Mg2Si peaks was found to decrease in samples sintered at higher temperature. Temperature dependent magnetic moment measurements showed that the superconducting transition temperature, Tc decreases as the SiC addition level increases while lower sintering temperature degrades Tc to a greater extent. The changes in the physical properties is discussed based on the results of phase formation, full width half maximum (FWHM), lattice parameter and crystallite size.

Structural and Dielectric Analysis of La0.88Bi0.12Mn0.80Ni0.20O3 Composite

2021 ◽  
Vol 317 ◽  
pp. 35-45
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Zainal Abidin Talib ◽  
Chen Soo Kien ◽  
Abdul Halim Shaari ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
A Value ◽  
Electric Behavior

Composite La0.88Bi0.12Mn0.80Ni0.20O3 was synthesized using the conventional solid-state reaction method with sintering temperature of 1200 °C for 12 hours and the dielectric properties investigated. The X-ray diffraction result shows that the composite has a rhombohedral structure with lattice parameter of a = b = c = 5.5136 Ǻ. Scanning electron microscope shows grains with approximately from 0.8 to 5.4 μm in size with presence of voids. The dielectric permittivity, εʹ and dielectric loss, εʺ were measured in the range of 298 K to 473 K where both are temperature and frequency dependent. At 1 kHz to 100 kHz, the εʹ is around 10000 and the dielectric loss tangent, tan δ is below 1.5. The electric behavior of this composite is best represented by Quasi-dc model which consists of two universal capacitors in parallel. Parameters value from the fitting indicated that high correlations of electrons between inter and intra-clusters. The activation energy, Ea calculated from the conductivity of the sample gives a value of 0.116 eV. Vibrating sample magnetometer shows that the La0.88Bi0.12Mn0.80Ni0.20O3 has a magnetic coercivity, Hc of 36.109 G and retentivity, Br, valued 2.7504 x 10-3 emu/g.

Properties and Phase Shift Structure of (1-x)BT-(x)BNT Ceramics

2016 ◽  
Vol 675-676 ◽  
pp. 615-618
Author(s):  
Chompoonuch Warangkanagool
Keyword(s):  
Sintering Temperature ◽  
Sodium Titanate ◽  
Lattice Parameter ◽  
Bismuth Sodium Titanate ◽  
X Ray Diffraction ◽  
Fluid Medium ◽  
X Ray ◽  
Xrd Patterns ◽  
Bismuth Sodium ◽  
Scanning Electron

In the research, the properties of barium titanate - bismuth sodium titanate [(1-x)BaTiO3-(x)Bi0.5Na0.5TiO3: (1-x)BT-(x)BNT] ceramics prepared by conventional mixed oxide method with various molecular weight of BNT or x between 0.0 and 0.3 were investigated. The optimum condition for calcined powders of x = 0.0 was found at 900 °C for 2 h, and x = 0.1 - 0.3 were found at 850 °C for 2h. The calcined powders were pressed and sintered at 1000 – 1200 °C for 2h. The phase structure was examined by x-ray diffraction (XRD). The microstructure was examined by scanning electron microscopy (SEM). Density of sintered samples was measured by Archimedes method with distilled water as the fluid medium. It was found that, all various x of (1-x)BT-(x)BNT ceramics XRD patterns display the tetragonality increased with increasing sintering temperature. All the peaks shift to higher angles when increasing x value indicating the decrease of lattice parameter “a” and increase of lattice parameter “c”. The average grains size of (1-x)BT-(x)BNT ceramics was increased with increasing sintering temperature. The highest density was 5.53 g/cm3 and was obtained from the sample sintered at 1200 °C.

Antiferromagnetic behavior in Y–Ba–(Cu1−xScx)–O

1989 ◽  
Vol 4 (3) ◽  
pp. 467-469 ◽  
Author(s):  
A. Chakraborty ◽  
X. D. Chen ◽  
F. Zuo ◽  
B. R. Patton ◽  
J. R. Gaines ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Composition Range ◽  
Second Phase ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Susceptibility Study ◽  
New Phase ◽  
Antiferromagnetic Behavior

We report the results on x-ray diffraction and magnetic susceptibility study of Y–Ba–(Cu1−xScx)–O. The materials were prepared in a stoichiometry corresponding to Y1Ba2(Cu1−xScx)3O7. Although x-ray analysis reveals the increasing presence of a subtle second phase with increasing Sc content, the superconducting transition temperature and resistivity did not change substantially in the composition range 0.0  x ≤ 0.15. In contrast, the magnetic susceptibility studies showed dramatic changes. Although Sc3+ has no spin by itself, an enhanced paramagnetic Curie susceptibility was observed above Tc with a moment of 1.5 μB per Sc. At 16 K a sharp cusp is observed in the temperature dependent susceptibility corresponding to the onset of a three-dimensionally ordered antiferromagnetic state. These results are discussed in terms of an additional previously unreported phase of Y–Ba–(Cu–Sc)–O that has an antiferromagnetic Néel temperature of 16 K. For composition of x = 1.0, a new phase is formed which is nonmagnetic.

Deposition of Superconducting Thin Films of Magnesium Di-Boride on Various Substrates by Electroless Plating Process

2010 ◽  
Vol 654-656 ◽  
pp. 1840-1843
Author(s):  
Susil K. Putatunda ◽  
Khurpa S. Vijayaragavan ◽  
Gavin Lawes
Keyword(s):  
Thin Films ◽  
Electroless Plating ◽  
Magnesium Diboride ◽  
Superconducting Thin Films ◽  
Superconducting Transition ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Gold Silver

Superconducting thin films of magnesium diboride (MgB2) has been synthesized on various substrates such as gold, silver, copper and silicon using a novel electroless plating technique. The microstructures and the superconducting properties of these films have been characterized using X-ray diffraction, scanning electron microscopy and temperature dependent magnetometry. X-ray diffraction measurements confirm that the films are crystalline magnesium diboride with some impurity phases. Clear evidence for a superconducting transition in the magnetization measurements was observed.

Synthesis and Characterization of Nickel Manganite Ceramics by Polymeric Precursors Method

2016 ◽  
Vol 881 ◽  
pp. 123-127 ◽  
Author(s):  
A.C.B. de Oliveira ◽  
D.M.S. Ribeiro ◽  
C.G.P. Moraes ◽  
R.S. Silva ◽  
Nilson Santos Ferreira ◽  
...  
Keyword(s):  
Room Temperature ◽  
Sintering Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Precursor Method ◽  
Spinel Type ◽  
X Ray ◽  
Lower Resistivity

This work presents the synthesis and characterization of NTC ceramic (Negative coefficient Temperature) based on nickel manganite (NiMn2O4) produced by the polymeric precursor method. NiMn2O4 were sintered at 900-1200 °C during 3h to produce the ceramics samples. The effect of sintering temperature on microstructure and electric properties of the NiMn2O4 ceramics was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and temperature dependent resistance R(T) measurements. The XRD measurement indicated formation of cubic spinel-type structure of NiMn2O4. The crystallite size (as confirmed by XRD) and the particle size (as confirmed by SEM) increased as the sintering temperature increased from around 18nm (900 °C) to 100nm (1200 °C). All samples showed NTC behavior and, among the studied ceramics, that one sintered at 1200 °C showed lower resistivity value (~103Ω.cm) at room temperature.

INVESTIGATION OF SUPERCONDUCTIVITY IN Y–Sr–Cu–O

1990 ◽  
Vol 04 (03) ◽  
pp. 195-199 ◽  
Author(s):  
R. SURYANARAYANAN ◽  
S. B. BALIGA ◽  
A. L. JAIN ◽  
O. GOROCHOV
Keyword(s):  
Magnetic Susceptibility ◽  
Nominal Composition ◽  
Ferromagnetic Transition ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature

Preparation, X-ray diffraction (XRD), resistivity (ρ) and magnetic susceptibility (χ) of YSrCuO y (nominal composition) synthesized at 1200°C are reported. XRD data indicate more than one phase. Zero resistivity is observed at 72 K. The field cooled χ indicates a superconducting transition at 68 K and also an anti-ferromagnetic transition at 15 K which could be due to Y 2 Cu 2 O 5. These data confirm the earlier observations of Wu et al.5 who have, however, observed a higher T c at 85 K which could be due to a higher temperature used for synthesis.

Solidification Behavior of Rapidly Quenched LaFe13-xSix Alloys

2013 ◽  
Vol 631-632 ◽  
pp. 62-66
Author(s):  
Zhong Qi Dong ◽  
Jun Suo Li ◽  
Ti Wen Han ◽  
Jin Chen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Diffraction Analysis ◽  
Cooling Rate ◽  
Phase Formation ◽  
Primary Phase ◽  
Solidification Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Solidification behavior of LaFe13-xSixalloys was investigated using rapidly quenching and. Phase formation and structure in rapidly quenched LaFe13-xSixalloys has been investigated by means of power X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The results have shown that 1:13 phase is a peritectic phase. The solidification behavior of LaFe13-xSix alloys depend on x, cooling rate. Under small undercooling, the 1:13 phase is difficult to formed with x=0.5 to 3.0. The α-(Fe,Si) phase and the 1:2:2 phase is mainly phase in the microstructure of alloy with low and high Si contents, respectively. Under higher cooling rate, the microstructure of compositions with x≥1.5 occurs the 1:13 phase. The α-(Fe,Si) phase and the 1:13 phase is mainly phase in the microstructure of alloy with low and high Si contents, respectively. The microstructure of compositions with x=2.5 to 3.0 are mainly phase which is primary phase. The results were discussed with respect to the effect of cooling rate.

Effect of Temperature on La1.85Sr0.15CuO4 Single Crystal Growth by Floating Zone Method

2007 ◽  
Vol 546-549 ◽  
pp. 1897-1900 ◽  
Author(s):  
X.Q. Xiang ◽  
J.F. Qu ◽  
Y.Q. Zhang ◽  
X.L. Lu ◽  
X.G. Li
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Effect Of Temperature ◽  
Superconducting Transition ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
Zone Method ◽  
Floating Zone Method ◽  
X Ray ◽  
Higher Temperature

Superconducting single crystals of La1.85Sr0.15CuO4 have been grown at various temperatures without single crystal seeds by the traveling-solvent floating-zone method. In order to avoid the formation of bubbles during the crystal growth process, a flowing atmosphere of 2 atm oxygen or 1 atm air was applied in different temperature range. It was found that the crystal quality could be improved by raising the growth temperature in a certain range, and the orientation changed from (110) to (100) at higher temperature. X-ray diffraction results showed that the full-width at half-maximum of the best as-prepared crystal was 0.086°. The crystals grown in 2 atm oxygen showed a superconducting transition temperature (Tc) of 37.3 K, while the crystals grown in floating air showed a Tc of about 35 K and it could be improved to 36.5 K by annealing in flowing oxygen.

scholarly journals Microstructure and Complex Permeability Spectra of Polycrystalline Cu-Zn Ferrites

2012 ◽  
Vol 4 (3) ◽  
pp. 551-560 ◽  
Author(s):  
Shahida Akhter ◽  
D. P. Paul ◽  
M. A. Hakim ◽  
S. Akhter ◽  
D. K. Saha ◽  
...  
Keyword(s):  
Single Phase ◽  
Sintering Temperature ◽  
Lattice Parameter ◽  
Initial Permeability ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zn Concentration ◽  
Zn Ferrite ◽  
Zn Content

Cu-Zn ferrites of composition Cu1-xZnxFe2O4 were prepared by double sintering ceramic technique at 9500C and 10500C for 3 hours and 2 hours, respectively. Structural and magnetic properties of the Cu-Zn ferrites were investigated by using X-ray diffraction, microstructure study and complex permeability behaviour. X-ray analysis indicated the formation of single-phase cubic spinel structure for all samples. The lattice parameter was found to increase with increasing Zn content obeying Vegard’s law. The X-ray and bulk densities of the Cu-Zn ferrite significantly decreased whereas porosity increased with increasing Zn concentration. Micrographs exhibited decrease in grain size with increasing concentrations. The real part ?’of initial permeability remained constant up to certain lower range of frequency after which it decreased to lower value of permeability. ?’ increased with increasing Zn contents up to x = 0.5, after that it decreased with higher Zn content but  was also found to increase with sintering temperature. The possible reasons responsible for change in structural, microstructural and complex permeability with increasing of non-magnetic Zn2+ ion are ascertained.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i3.10798 J. Sci. Res. 4 (3), 551-560 (2012)

Growth of MonX by Reactive Laser ablation

1995 ◽  
Vol 388 ◽  
Author(s):  
Randolph E. Treece ◽  
James S. Horwitz ◽  
Edward Donovan ◽  
Douglas B. Chrisey
Keyword(s):  
Electronic Transport ◽  
Pulsed Laser ◽  
Fused Silica ◽  
Laser Deposition ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Temperature Dependent Resistivity ◽  
Background Gas

AbstractControl of composition and phase of a series of MoNx thin films has been accomplished by reactive pulsed laser deposition (PLD). Molybdenum foil targets were ablated in a background gas of N2/H2 (10%) at pressures ranging from 40 to 120 mTorr. the MoNx films were deposited simultaneously onto (100) MgO and fused silica substrates. the films were characterized by X-ray diffraction (XRD), temperature-dependent resistivity, and Rutherford backscattering spectroscopy (RBS). the composition, phase, and electronic transport properties were found to depend on N2/H2 pressure, substrate temperature, and substrate orientation. the highest superconducting transition temperature (Tc ) was observed in a hexagonal Mo2N film where Tc (onset) ≈ 8 K. IN general, Tc was observed to correlate most closely with the N/Mo ratio. as the ratio of N/Mo increased above optimal M02N composition, Tc decreased. Films grown on MgO generally had higher N/Mo ratios and hence lower Tc values than films deposited on silic A.

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