scholarly journals Structural, electrical and magnetic properties of the pyrochlorate Er_2-x Sr_x Ru_2O_7 (0<=x<=0.10) system

2018 ◽  
Vol 64 (3) ◽  
pp. 222 ◽  
Author(s):  
Mohamed Abatal
Keyword(s):  
Magnetic Properties ◽  
Crystal Size ◽  
Rietveld Method ◽  
Ambient Pressure ◽  
Zero Field ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Increasing Temperature

In this research, we report a detailed study of the structural, electrial and magnetic properties of the ruthenium pyrochlore with the composition (Er_2-x Sr_x) Ru_2O_7 0<=x<=0.10 prepared by solid-state reaction in air at ambient pressure.  The synthesized products were characterized using powder X-ray diffraction. The structure of the samples was refined with the Rietveld method, showing that the lattice parameters are more sensitive to the Strontium and Erbium sites. Scanning electron microscopy shows that the crystal size varies between 0.27 and 0.62 mu m. In all polycrystalline samples, the electrical resistance decreases with increasing temperature, indicating that the samples are nonmetallic. The slope of the temperature-dependent resistance profiles systematically decreases with increasing x, proving that the carrier concentration increases with increasing the Sr content. Zero-field-cooled and field cooled magnetization measurements show an irreversible behavior where the split is systematically enhanced by increasing x.

scholarly journals Structural and thermoelectric properties of the Pr2Zr2O7 compound

2019 ◽  
pp. 4-9
Author(s):  
Adolfo Quiroz-Rodríguez ◽  
Cesia Guarneros-Aguilar ◽  
Ricardo Agustin-Serrano
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Crystal Size ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Scanning Electron

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

scholarly journals Influence of Li2CO3 addition on electrical and magnetic properties of Ni0.6Mg0.4Fe2O4

2020 ◽  
Vol 10 (03) ◽  
pp. 2050003
Author(s):  
M. R. Hassan ◽  
M. T. Islam ◽  
M. N. I. Khan
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Low Frequency ◽  
Solid State Reaction Method ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Frequency Regime ◽  
Xrd Patterns

In this research, influence of adding Li2CO3 (at 0%, 2%, 4%, 6%) on electrical and magnetic properties of [Formula: see text][Formula: see text]Fe2O4 (with 60% Ni and 40% Mg) ferrite has been studied. The samples are prepared by solid state reaction method and sintered at 1300∘C for 6[Formula: see text]h. X-ray diffraction (XRD) patterns show the samples belong to single-phase cubic structure without any impurity phase. The magnetic properties (saturation magnetization and coercivity) of the samples have been investigated by VSM and found that the higher concentration of Li2CO3 reduces the hysteresis loss. DC resistivity increases with Li2CO3 contents whereas it decreases initially and then becomes constant at lower value with temperature which indicates that the studied samples are semiconductor. The dielectric dispersion occurs at a low-frequency regime and the loss peaks are formed in a higher frequency regime, which are due to the presence of resonance between applied frequency and hopping frequency of charge carriers. Notably, the loss peaks are shifted to the lower frequency with Li2CO3 additions.

A temperature-dependent structure study of gem-quality hibonite from Myanmar

2010 ◽  
Vol 74 (5) ◽  
pp. 871-885 ◽  
Author(s):  
M. Nagashima ◽  
T. Armbruster ◽  
T. Hainschwang
Keyword(s):  
Room Temperature ◽  
Structure Study ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Trigonal Bipyramidal ◽  
Expansion Coefficients ◽  
Increasing Temperature ◽  
Length Distortion

AbstractThe structure of hibonite from Myanmar (space group P63/mmc, Z = 2, at room temperature a = 5.5909(1), c = 21.9893(4) Å), with simplified formula CaAl12O19 and composition (Ca0.99Na0.01)Σ1.00 was investigated between temperatures of 100 K and 923 K by single-crystal X-ray diffraction methods. Structure refinements have been performed at 100, 296, 473 and 923 K. In hibonite from Myanmar, Ti substitutes for Al mainly at the octahedral Al4 site and, to a lesser degree, at the trigonal bipyramidal site, Al2. The Al4 octahedra build face-sharing dimers. If Ti4+ substitutes at Al4, adjacent cations repulse each other for electrostatic reasons, leading to off-centre cation displacement associated with significant bond-length distortion compared to synthetic (Ti-free) CaAl12O19. Most Mg and smaller proportions of Zn and Si are assigned to the tetrahedral Al3 site. 12-coordinated Ca in hibonite replaces oxygen in a closest-packed layer. However, Ca is actually too small for this site and engages in a ‘rattling-type’ motion with increasing temperature. For this reason, Ca does not significantly increase thermal expansion coefficients of hibonite. The expansion of natural Ti,Mg-rich hibonite between 296 and 923 K along the x and the z axes is αa = 7.64×10–6 K–1 and αc = 11.19×10–6 K–1, respectively, and is thus very similar to isotypic, synthetic CaAl12O19 and LaMgAl11O19 (LMA).

Application of Gel Technology in Preparation of High-Tc Perovskite Superconductors

1987 ◽  
Vol 99 ◽  
Author(s):  
R. S. Liu ◽  
G. C. Lin ◽  
H. M. Sung ◽  
Y. C. Chen ◽  
O. C. C. Lin
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Diffraction Analysis ◽  
Dicarboxylic Acids ◽  
X Ray Diffraction ◽  
Chemical Homogeneity ◽  
High Tc ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
High Degree

ABSTRACTLa-Ba-Cu-O and Y-Ba-Cu-O superconducting systems have been successfully prepared by gel techniques with high degree of chemical homogeneity. The precursor gel was synthesized from mixture of the corresponding metallic nitrates and di-carboxylic acids. The sintered oxides prepared from the different dicarboxylic acids were all Tc = 90K perovskite superconductors. However differences in electrical and magnetic properties were also observed. Effects due to the different acids elucidated by magnetic susceptibility measurements and X-ray diffraction analysis will be discussed.

Grain Size Dependent Magnetic Properties of Nanocrystalline Sm [BE]Co [BD][BJ]/Cu

2001 ◽  
Vol 703 ◽  
Author(s):  
L. Bessais ◽  
C. Djéga-Mariadassou ◽  
J. Zhang ◽  
V. Lalanne ◽  
A. Percheron-Guégan
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Rietveld Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size Dependent ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Magnetic Metal ◽  
Chemical Distribution

ABSTRACTThe evolution of both micro structural and magnetic properties of the Sm[BE]Co[BD][BJ] Cu powder, is studied as a function of soft co-milling time. The average grain size in the range 20 - 50 nm was determined by transmission electron microscopy coupled with x-ray diffraction using the Rietveld method. The particle shape and chemical distribution were investigated by elemental mapping, using wavelength dispersive x-ray analysis with electron microprobe analysis. The coercivity evolution shows that an optimum value of 6 kOe is obtained after 5 h co-milling. The microstructure analysis indicates that both materials are well mixed in nanometer scale. This technique appears as a potential route to synthesize nanocrystalline Sm[BE]Co[BD][BJ] isolated by non-magnetic metal Cu.

Superconductivity and Normal-State Properties of (Y1-x-yZrxCay)Ba2Cu3O7-δ Compounds

1998 ◽  
Vol 12 (28) ◽  
pp. 1175-1183 ◽  
Author(s):  
I. Gr. Deac ◽  
A. V. Pop ◽  
V. Pop ◽  
R. Tetean ◽  
D. Kovacs ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Powder Diffraction ◽  
Normal State ◽  
Lattice Parameters ◽  
Temperature Dependent ◽  
Dopant Content ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Normal State Properties

The electrical and magnetic properties of ( Y 1-x-y Zr x Ca y) Ba 2 Cu 3 O 7-δ ceramics are investigated by using resistivity, ac and dc susceptibility measurements. X-ray powder diffraction has been used to find the lattice parameters of the samples. The samples are orthorhombic, except the sample with x=0.15 and y=0.2 which is tetragonal. All the samples are superconducting. There is no significant change in Tc for the Zr-doped ( Y 1-x Zr x) Ba 2 Cu 3 O 7-δ samples, while for the ( Y 0.85-y Zr 0.15 Ca y) Ba 2 Cu 3 O 7-δ compounds the Tc decrease with the dopant content and they show temperature dependent dc magnetic susceptibility, in the normal state.

scholarly journals Synthesis and characterization of Na-P1 (GIS) zeolite using a kaolinitic rock

2020 ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Alessandro Del Vecchio
Keyword(s):  
Inductively Coupled Plasma ◽  
Rietveld Method ◽  
Ambient Pressure ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Inductively Coupled

Abstract This work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 ° and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods.The results make the experimental protocol very promising for an industrial transfer.

Darstellung und magnetische Eigenschaften einiger kristalliner Nitroxidradikale/Synthesis and Magnetic Properties of Some Crystalline Nitroxide Radicals

2000 ◽  
Vol 55 (7) ◽  
pp. 567-575 ◽  
Author(s):  
K. Griesar ◽  
E. A. Soto-Bustamante ◽  
W. Haase
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Properties ◽  
Exchange Interactions ◽  
Antiferromagnetic Exchange ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Nitroxide Radicals ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
X Ray

Abstract The syntheses of different nitroxide radicals are reported. The thermal behaviour of the ni­ troxide radicals was examined by polarizing microscopy, differential scanning calorimetry as well as X-ray diffraction experiments. Temperature dependent magnetic susceptibility mea­surements were carried out in order to determine the magnetic properties of these nitroxide radicals. The majority of the radicals presented here show weak antiferromagnetic exchange interactions.

Investigation of Magnetic Properties and Nanostructure of Fe2.75Mn0.25O4@ PANI Materials and their Potential as the Magnetic Ink

2020 ◽  
Vol 855 ◽  
pp. 308-314
Author(s):  
Nadiya Miftachul Chusna ◽  
Sunaryono ◽  
Yunan Amza Muhammad ◽  
Rosabiela Irfa Andin ◽  
Ahmad Taufiq
Keyword(s):  
Magnetic Properties ◽  
Crystal Size ◽  
In Situ Polymerization ◽  
Xrd Analysis ◽  
Hysteresis Curve ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polymerization Method

The Fe2.75Mn0.25O4 nanoparticles were successfully synthesized by using the coprecipitation method, while the Fe2.75Mn0.25O4@PANI materials were successfully fabricated by using the in situ polymerization method. This research aimed to investigate the magnetic properties and nanostructure of the Fe2.75Mn0.25O4 nanoparticles and Fe2.75Mn0.25O4@PANI materials. Some characterizations of the samples were successfully carried out by using X-Ray Diffraction (XRD) instruments, Fourier Transform Infrared (FTIR), and Vibrating Sample Magnetometer (VSM) each of which was conducted to characterize the crystal structure, functional groups, morphology, and the magnetic properties of the materials. The XRD analysis results showed that the Fe2.75Mn0.25O4@PANI materials had a crystal size of 8.09 nm. Meanwhile, the FTIR spectrum represented vibrations due to the atomic bonds that made up the Fe2.75Mn0.25O4@PANI materials. Furthermore, the hysteresis curve from the VSM characterization results showed that the Fe2.75Mn0.25O4@PANI material saturation magnetization value was around 2.85 emus/g. From those characterization results, the Fe2.75Mn0.25O4@PANI materials are very potential to be applied as magnetic ink

Structural and magnetic variations in Ba0.5Sr0.5Fe9Ce1Al2O19 hexaferrites at different sintering temperatures

2021 ◽  
Author(s):  
A.R. Makhdoom ◽  
Qasim Ali Ranjha ◽  
Ubaid-ur-Rehman Ghori ◽  
Muhammad Ahsan Raza ◽  
Binish Raza ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Recording Media ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
X Ray ◽  
Pure Phase ◽  
Different Temperatures ◽  
Diffraction Patterns ◽  
Increasing Temperature

Abstract M-type hexaferrites has attracted researchers due to their ordinary magnetic properties and utilization as media for magnetic recording and microwave devices. In this study we have synthesized Ba0.5Sr0.5Fe9Ce1Al2O19 via conventional ceramic route. The synthesized material is treated against different temperatures and investigated structurally and magnetically by using several techniques such as X-ray diffraction, Scanning electron microscopy, and VSM respectively. Morphology of samples confirms the absence of secondary phases and uniform distribution of particles. X-ray diffraction patterns confirms the formation of pure phase of Hexaferrites. Microstructural analyses show the decrease in porosity and dislocations among sintered samples. Magnetic properties for the samples show a decrease in Ms and Mr with increasing temperature from 1225 °C to 1310 °C, while coercivity shows an increase with increasing temperature and maximum coercivity is observed at 1290 °C. The trends and occurrences can be well-linked to the structural variations and sintering effects. The results suggest that material can be used in various magnetic applications such as Recording media, and memory devices.

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