THE EFFECT OF La AND Sn DOPING ON THE STRUCTURAL AND MAGNETIC PROPERTIES OF RuSr2EuCeCu2Oz

2005 ◽  
Vol 19 (01n03) ◽  
pp. 353-359 ◽  
Author(s):  
H. K. LEE ◽  
H. M. Park ◽  
G. V. M. Williams
Keyword(s):  
Magnetic Properties ◽  
Volume Fraction ◽  
Magnetic Ordering ◽  
Structural Data ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
Sn Doping ◽  
Ferromagnetic Component ◽  
La Substitution ◽  
Induced Changes

The crystal structure and magnetic properties of ( Ru 1-x Sn x) Sr 2 EuCeCu 2 O z and Ru ( Sr 2-x La x) EuCeCu 2 O z(0≤ x ≤0.1) samples have been investigated to shed light on the doping-induced changes in the magnetic properties of Ru -1222 system. We show that La substitution for Sr leads to an increase in the temperature where the ferromagnetic component is observed and a moderate suppression of the ferromagnetic component whereas Sn substitution for Ru results in a significant decrease of the volume fraction of the ferromagnetic phase as well as a decrease in the magnetic ordering temperature. The experimental results are discussed in connection with the structural data studied by Rietveld refinement of the x-ray diffraction data.

Structure, Microsctructure and Magnetic Properties of Ternary (Fe0.6Al0.4)100-xSix Nanostructured Powders: Effect of Si Addition

2019 ◽  
Vol 58 ◽  
pp. 102-117 ◽  
Author(s):  
N. Boukherroub ◽  
M. Hemmous ◽  
A. Guittoum ◽  
D. Martínez-Blanco ◽  
N. Souami ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Volume Fraction ◽  
Lattice Parameter ◽  
Ternary Alloys ◽  
Ferromagnetic Phase ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Order Of Magnitude ◽  
Powder Particles ◽  
Si Content

Nanostructured (Fe0.6Al0.4)100-xSix powders with x= 0, 5, 10, 15 and 20 at.% were elaborated by means of mechanical alloying for a fixed milling time of 72 h. We have investigated the effect of silicon addition on the microstructure and magnetic properties of these ternary alloys. X-ray diffraction experiments reveal that these powders are single-phase disordered solid solutions with body centered cubic crystal structure. The lattice parameter diminishesalmost linearly as the Si content increases. The mean crystallite size,<D(nm)>, is around three times smaller for the samples with higher amount of Si (≈ 10 nm) compared with that of the binary alloy (27 nm). Moreover, the volume fraction of grain boundaries (fgb) seems to be higher with increasing the Si content, as well as both dislocation density (ρ) and lattice microstrain (<ε>),that follow alinear trend. The SEM images show that the Si helps in refining the shape and size of the powder particles, leading to a nearly homogeneous small particles.The addition of Si strongly affects the value of the saturation magnetization, Ms, that falls nearly an order of magnitude for the sample with 20 at.% Si, while the coercivity remains almost unchanged. The Mössbauer spectra show the presence of a sextet (ferromagnetic phase) and a singlet or a doublet (non ferromagnetic phase), except for the sample corresponding to x = 10, where only one singlet is observed in the spectrum.

Preparation of LaFeO3 particles by sol-gel technology

1998 ◽  
Vol 13 (2) ◽  
pp. 451-456 ◽  
Author(s):  
C. Vázquez-Vázquez ◽  
P. Kögerler ◽  
M. A. López-Quintela ◽  
R. D. Sánchez ◽  
J. Rivas
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Infrared Spectroscopy ◽  
Sol Gel ◽  
Diffraction Peak ◽  
Gel Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferromagnetic Component ◽  
Peak Broadening

The study of submicroscopic particles in already known systems has resulted in a renewed interest due to the large differences found in their properties when the particle size is reduced, and because of possible new technological applications. In this work we report the preparation of LaFeO3 particles by the sol-gel route, starting from a solution of the corresponding metallic nitrates and using urea as gelificant agent. Gels were decomposed at 200 °C and calcined 3 h at several temperatures, T, in the range 250–1000 °C. The samples were structurally characterized by x-ray diffraction (XRD) showing that the orthoferrite crystallizes at T as low as 315 °C. From the x-ray diffraction peak broadening, the particle size was determined. The size increases from 60 to 300 nm as the calcination T increases. Infrared spectroscopy was used to characterize gels and calcined samples. From these studies a mechanism for the gel formation is proposed. Study of the magnetic properties of LaFeO3 particles shows the presence of a ferromagnetic component which diminishes as the calcination temperature increases, vanishing at T = 1000 °C.

scholarly journals Nanostructure-Related Magnetic Properties of Various Mesoporous Cobalt Oxide and Cobalt Ferrite Spinel Phases

2019 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Magnetic Properties ◽  
Cobalt Oxide ◽  
Cobalt Ferrite ◽  
Magnetic Ordering ◽  
Magnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Phases ◽  
Ferrite Spinel

Nanostructure-related magnetic properties are investigated systematically for various mesoporous cobalt oxide (Co3O4) and cobalt ferrite (CoFe2O4) spinel phases. Synthesis of thematerials by nanocasting offers the opportunity to obtain materials which are different from each other with respect to both specific surface area and crystallite size. As a result, the respective contributions of two types of interfaces, namely, “solid–gas” and “solid–solid” interfaces, to the magnetic ordering can be distinguished. Structural characterization of the porous materials by X-ray diffraction, N2 physisorption, and electron microscopy as well as investigation of the magnetic behavior (field-dependent magnetization and temperaturedependentsusceptibility) are presented.

scholarly journals Pressure Induced Spin Crossover and Magnetic Properties of Multiferroic Ba3NbFe3Si2O14

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3808
Author(s):  
Igor Lyubutin ◽  
Sergey Starchikov ◽  
Ivan Troyan ◽  
Yulia Nikiforova ◽  
Marianna Lyubutina ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spin Crossover ◽  
High Pressures ◽  
Magnetic Ordering ◽  
Radical Change ◽  
Structural Transitions ◽  
X Ray Diffraction ◽  
Structural And Electronic Properties ◽  
Diamond Anvil ◽  
Synchrotron Mössbauer Source

Recently, the iron containing langasite-type crystal Ba3NbFe3Si2O14 has attracted great attention as a new magnetically induced multiferroic. In this work, magnetic, structural and electronic properties of the multiferroic Ba3NbFe3Si2O14 were investigated by several methods, including synchrotron X-ray diffraction, Raman spectroscopy and synchrotron Mössbauer source technique at high quasi-hydrostatic pressures (up to 70 GPa), created in diamond anvil cells. At room temperature, two structural transitions at pressures of about 3.0 and 17.5 GPa were detected. Mössbauer studies at high pressures revealed a radical change in the magnetic properties during structural transitions. At pressures above 18 GPa, the crystal transforms into two magnetic fractions, and in one of them the Néel temperature (TN) increases by about four times compared with the TN value in the initial phase (from 27 to 115 K). At pressures above 50 GPa, a spin crossover occurs when the fraction of iron Fe3+ ions in oxygen octahedra transits from the high-spin (HS, S = 5/2) to the low-spin (LS, S = 1/2) state. This leads to a new change in the magnetic properties. The magnetic ordering temperature of the LS sublattice was found to be of about 22(1) K, and magnetic correlations between HS and LS sublattices were studied.

TRANSPORT AND MAGNETIC PROPERTIES OF Bi BASED MULTIPHASE SUPERCONDUCTORS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3741-3743 ◽  
Author(s):  
P. Vašek ◽  
I. Janeček
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Volume Fraction ◽  
The Other ◽  
Hall Voltage ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effective Medium Approach

A series of (Bi,Pb)SrCuCaO samples with varying volume fraction of the 2223 phase (determined by X-ray diffraction) has been prepared. Temperature dependence of the resistance, Hall effect and magnetic susceptibility has been measured. Neither susceptibility (both dc and ac) nor electrical resistivity in magnetic field reveal the presence of the low temperature (2212) phase. On the other hand the Hall voltage in the mixed state is very sensitive to the presence of different phases. Obtained results have been discussed within the frame of the effective medium approach and related to the growth mechanism of the 2223 phase.

High-pressure Synthesis and Structural, Electrical and Magnetic Properties of a New Filled Skutterudite TbFe4P12

2006 ◽  
Vol 61 (12) ◽  
pp. 1471-1476 ◽  
Author(s):  
Ichimin Shirotani ◽  
Keiki Takeda ◽  
Chihiro Sekine ◽  
Junichi Hayashi ◽  
Ryusuke Nakada ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Ambient Pressure ◽  
Magnetic Ordering ◽  
Ferromagnetic Transition ◽  
X Ray Diffraction ◽  
Filled Skutterudite ◽  
Electrical And Magnetic Properties ◽  
Linear Slope ◽  
The Relationship

The new filled skutterudite TbFe4P12 has been prepared at around 4 GPa and 1050 °C. Powder X-ray diffraction of TbT4P12 (T = Fe and Ru) has been studied with synchrotron radiation at ambient pressure. The crystal structures of both compounds were refined by Rietveld methods at ambient pressure. The positional parameters, bond lengths and bond angles have been obtained for TbT4P12 (T = Fe and Ru). The electrical and magnetic properties of TbFe4P12 have been investigated at low temperatures. The susceptibility of this phosphide follows a Curie-Weiss behavior at higher temperatures. The linear slope of the χ−1 vs. T curve from 15 to 300 K yields an effective magnetic moment of 9.48 μB. This value is close to the magnetic moment of the Tb3+ ion calculated from Hund’s rule, 9.72 μB. The ferromagnetic transition of TbFe4P12 was observed at around 10 K, and an electrical anomaly based on the magnetic ordering was detected. The relationship between the crystal structure and the physical properties of TbT4P12 (T = Fe and Ru) is discussed.

Structure and Electrical Properties of PbTiO3-CoFe2O4 Magnetoelectric Composites

2011 ◽  
Vol 687 ◽  
pp. 174-178 ◽  
Author(s):  
Jing Song Liu ◽  
You Chao Xu ◽  
Tao Li
Keyword(s):  
Magnetic Properties ◽  
Solid State ◽  
Ferroelectric Phase ◽  
Volume Fraction ◽  
Solid State Reaction Method ◽  
Ferromagnetic Phase ◽  
Test Frequency ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Magnetoelectric Composites

0-3 type magnetoelectric(ME) composites of PbTiO3(PT) and CoFe2O4(CFO) were prepared by a conventional solid-state reaction method with different volume fraction. The composites exhibited ferroelectric phase and ferromagnetic phase coexisting. The ferroelectric and magnetic properties of as-sintered samples were measured. The magnetic properties change regularly with the test frequency. But the dielectric permittivity shows the anomalies, which can be attributed to constraints and dilutions from the ferromagnetic phase and the element diffusion.

Dielectric and Magnetic Properties of CoFe2O4-BaTiO3 Composite Thick Film

2009 ◽  
Vol 421-422 ◽  
pp. 219-222
Author(s):  
Ling Zhang ◽  
Ji Wei Zhai ◽  
Wei Feng Mo ◽  
Xi Yao
Keyword(s):  
Magnetic Properties ◽  
High Temperature ◽  
Dielectric Properties ◽  
Thick Film ◽  
Low Frequency ◽  
Ferromagnetic Phase ◽  
Deposition Technique ◽  
X Ray Diffraction ◽  
Charge Effects ◽  
X Ray

(x)CoFe2O4-(1-x) BaTiO3 thick film with x=0.2 was prepared by electrophoretic deposition technique using BaTiO3 and CoFe2O4 nanopowders. X-ray diffraction indicated the film was consisted of single spinel CoFe2O4 and perovskite BaTiO3 phase. The thick film exhibited good ferromagnetic and ferroelectric property. The dielectric properties were influenced by ferromagnetic phase, especially at low frequency and high temperature, which was attributed to space charge effects and Maxwell-Wagner relaxation.

Hydrothermal Synthesis of Ce/Zr co-substituted BiFeO3: R3c-to-P4mm Phase Transition and Enhanced Room Temperature Ferromagnetism

2021 ◽  
Author(s):  
Zahra Adineh ◽  
Ahmad Gholizadeh
Keyword(s):  
Phase Transition ◽  
Magnetic Properties ◽  
Raman Spectra ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Magnetic Transition ◽  
Ferromagnetic Phase ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Vis Spectroscopy

Abstract A facile hydrothermal method was used for fabricating phase-pure Bi1 − xCexFe1−xZrxO3 (x = 0.00, 0.03, 0.06) multiferroic ferrites, and the dependence of structural, optical, and magnetic properties on the composition have been investigated. The samples were investigated by X-ray diffraction (XRD), Raman and Fourier-transform infrared (FT-IR) spectroscopies, scanning electron microscopy, UV-Vis spectroscopy, and vibrating sample magnetometer at room temperature. Structural results show that the structure of Bi1 − xCexFe1−xZrxO3 ferrites is indexed to a rhombohedral structure with R3c space group. However, the weakening in the intensity, the expansion of the line-width of all bands, and some band shifts observed in Raman spectra indicate a structural transition from rhombohedral (R3c) to pseudo-tetragonal (P4mm) phase as the content of Ce/Zr increases. Also, a significantly enhanced intensity of the A1-2 mode in Raman spectra means that there is a novel behavior of magnetic anisotropy in the Ce/Zr co-substituted samples. A significant increase in optical band gap with increasing of the Ce/Zr co-substitution suggests that the materials are suitable for technological applications. Magnetic properties of the samples show a magnetic transition from antiferromagnetic to ferromagnetic phase due to the presence of the rhombohedral to the tetragonal phase transition, and exchange interaction between the 4f orbitals of the Ce3+/Ce4+ and the 3d orbitals of the Fe3+/Fe2+.

Preparation, crystal structure and magnetic properties of the high-pressure phase MnReO4 with a wolframite-type structure

2005 ◽  
Vol 61 (3) ◽  
pp. 246-249 ◽  
Author(s):  
K. G. Bramnik ◽  
H. Ehrenberg ◽  
S. Buhre ◽  
H. Fuess
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Ordering ◽  
Type Structure ◽  
Ternary Oxide ◽  
X Ray Diffraction ◽  
Rhenium Oxide ◽  
Ionic Radii ◽  
Average Bond

The ternary oxide MnReO4, manganese rhenium oxide, has been synthesized under a high pressure of 5.5 GPa at 1473 K and its crystal structure has been determined by single-crystal X-ray diffraction. MnReO4 crystallizes in a wolframite-type structure with average bond lengths of 〈Re—O〉 = 1.935 and 〈Mn—O〉 = 2.160 Å that are in good agreement with the ionic radii of Re6+ and Mn2+. The magnetic properties of MnReO4 have been studied by SQUID measurements, revealing magnetic ordering below 275 (10) K and a weak ferromagnetic component of the ordered magnetic structure.

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