Superconductivity and Magnetic Ordering of Pr in CaLa1-xPrxBaCu3O7 System

1997 ◽  
Vol 11 (07) ◽  
pp. 323-331 ◽  
Author(s):  
V. P. S. Awana ◽  
Rajvir Singh ◽  
D. A. Landinez Tellez ◽  
J. M. Ferreira ◽  
J. Albino Aguiar ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Normal State ◽  
Ac Susceptibility ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Peak Intensity ◽  
Heat Capacity Measurements ◽  
A Minor

We present the results of superconductivity, normal state magnetic susceptibility and heat capacity measurements on the tetragonal CaLa 1-x Pr x BaCu 3 O 7 compound. Ac susceptibility measurements show that the transition temperature T c of the unsubstituted sample decreases with an increase in the Pr concentration. Normal state dc magnetic susceptibility measurements performed in an applied field of 0.5 T show a Curie–Weiss behaviour in terms of the paramagnetic moment of Pr. The effective paramagnetic moment of Pr appears to be intermediate between those of the free Pr 3+ and Pr 4+ ions. For the nonsuperconducting samples i.e., x = 0.70 and 1.0, we observe an antiferromagnetic ordering temperature T N of nearly 4 K and 8 K respectively. The X-ray diffraction results show that the CaPrBaCu 3 O 7 compound is free from other phases, having a minor (less than 8%, in terms of peak intensity) impurity phase. The lower T N (8 K) of PrBaCaCu 3 O 7 as compared to the known antiferromagnetic ordering temperature of 17 K for PrBa 2 Cu 3 O 7 indicates a less deleterious effect of Pr in the present case.

Ternary Antimonides RE4T7Sb6 (RE=Gd–Lu; T =Ru, Rh) with Cubic U4Re7Si6-type Structure

2013 ◽  
Vol 68 (9) ◽  
pp. 971-978 ◽  
Author(s):  
Inga Schellenberg ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Matthias Eul ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Moment ◽  
Induction Furnace ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Arc Melting ◽  
Intermediate Valent

The ternary antimonides RE4T7Sb6 (RE=Gd-Lu; T =Ru, Rh) have been synthesized from the elements by arc-melting and subsequent annealing in an induction furnace. The samples have been characterized by powder X-ray diffraction. Four structures were refined on the basis of single-crystal X-ray diffractometer data: U4Re7Si6 type, space group Im3m with a=862.9(2) pm, wR2=0.0296, 163 F2 values for Er4Ru7Sb6; a=864.1(1) pm, wR2=0.1423, 153 F2 values for Yb4Ru7Sb6; a=872.0(2) pm, wR2=0.0427, 172 F2 values for Tb4Rh7Sb6; and a=868.0(2) pm, wR2=0.0529, 154 F2 values for Er4Rh7Sb6, with 10 variables per refinement. The structures have T1@Sb6 octahedra and slightly distorted RE@T26Sb6 cuboctahedra as building units. The distorted cuboctahedra are condensed via all trapezoidal faces, and this network leaves octahedral voids for the T1 atoms. The ruthenium-based series of compounds was studied by temperature-dependent magnetic susceptibility measurements. Lu4Ru7Sb6 is Pauli-paramagnetic. The antimonides RE4Ru7Sb6 with RE=Dy, Ho, Er, and Tm show Curie-Weiss paramagnetism. Antiferromagnetic ordering occurs at 10.0(5), 5.1(5) and 4.0(5) K for Dy4Ru7Sb6, Ho4Ru7Sb6 and Er4Ru7Sb6, respectively, while Tm4Ru7Sb6 remains paramagnetic. Yb4Ru7Sb6 is an intermediate-valent compound with a reduced magnetic moment of 3.71(1) μB per Yb as compared to 4.54 μB for a free Yb3+ ion

Crystal Structure and Magnetic Ordering Transitions in CeNiIn4, EuNiIn4 and EuCuIn4

2014 ◽  
Vol 69 (9-10) ◽  
pp. 1003-1009 ◽  
Author(s):  
Walter Schnelle ◽  
Reinhard K. Kremer ◽  
Rolf-Dieter Hoffmann ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Low Temperatures ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Heats ◽  
Antiferromagnetic Ordering ◽  
Arc Melting ◽  
Ordering Transitions ◽  
The Eu

Abstract Polycrystalline CeNiIn4 was prepared by arc-melting of the elements and subsequent annealing at 970 K in vacuum. EuNiIn4 and EuCuIn4 were synthesized from the elements by reactions in sealed tantalum tubes. These indium-rich compounds crystallize with the YNiAl4-type structure which was refined for EuCuIn4 from single-crystal X-ray diffraction data: Cmcm, a=450:04(9), b=1698:7(4), c = 740:2(2) pm, wR2 = 0:0606, 495 F2 values, 24 variables. The EuCuIn4 structure is built up from a complex three-dimensional [CuIn4] polyanion (265 - 279 pm Cu-In and 296 - 331 pm In- In) in which the europium atoms occupy distorted hexagonal channels. The Eu-Eu distances within these channels (450 pm) are significantly shorter than the distances between Eu atoms in neighboring channels (552 pm). The magnetic properties and the specific heats of the europium compounds have been investigated. Both europium compounds show the magnetism of divalent Eu ions and antiferromagnetic ordering at low temperatures. EuCuIn4 is magnetically ordered via a surprisingly complex sequence of three transitions

Magnesium-rich Intermetallics RE3RuMg7 (RE=Y, Nd, Dy, Ho) – Rows of Condensed Ru@RE6/2 Octahedra in Magnesium Matrices

2013 ◽  
Vol 68 (12) ◽  
pp. 1273-1278 ◽  
Author(s):  
Marcel Kersting ◽  
Ute Ch. Rodewald ◽  
Christian Schwickert ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Moment ◽  
Small Degree ◽  
Intermetallic Phases ◽  
Metamagnetic Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Experimental Magnetic Moment

The magnesium-rich intermetallic phases RE3RuMg7 (RE=Y, Nd, Dy, Ho) have been synthesized from the elements in sealed niobium ampoules and subsequently characterized by powder X-ray diffraction. The structure of the dysprosium compound was refined on the basis of single-crystal X-ray diffractometer data: Ti6Sn5 type, P63=mmc, a=1019.1(2), c=606.76(9) pm, wR2=0.0159, 439 F2 values, 19 variables. The Mg3 site shows a small degree of Mg3=Dy mixing, leading to the composition Dy3:03RuMg6:97 for the investigated crystal. The striking structural motifs in the Dy3RuMg7 structure are rows of face-sharing Ru@Dy6 octahedra and corner-sharing Mg2@Mg8Dy4 icosahedra. The rows of octahedra form a hexagonal rod-packing, and each rod is enrolled by six rows of the condensed icosahedra. Temperature-dependent magnetic susceptibility measurements of Dy3RuMg7 show Curie-Weiss behavior with an experimental magnetic moment of 10.66(1) µB per Dy atom. Antiferromagnetic ordering is detected at TN =27.5(5) K. The 5 K isotherm shows a metamagnetic transition at a critical field of HC =40 kOe

Evolution of Magnetic Ordering in Spinel Oxide System: Mn1.5(1-x)Ti0.5(1-x)Fe(1+ 1.5x)Li(0.5)xO4

2013 ◽  
Vol 209 ◽  
pp. 27-30
Author(s):  
Vaishali P. Joshi ◽  
Ashish R. Tanna ◽  
Kalpesh H. Jani ◽  
H.H. Joshi
Keyword(s):  
Ac Susceptibility ◽  
Magnetic Hyperfine Field ◽  
Magnetic Ordering ◽  
Oxide System ◽  
Spinel Oxide ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Temperature And Growth

Six compositions: x = 0.0 to 0.5 of the spinel system Mn1.5(1-x)Ti0.5(1-x)Fe(1+ 1.5x) Li(0.5)x O4 are synthesized by ceramic method. The structural and magnetic properties are studied by means of X-ray diffraction, AC susceptibility, Magnetization and Mossbauer spectroscopy. The study reveals the significance of FeA-O-FeB magnetic linkages in evolution of long range magnetic ordering through rise in Curie temperature and growth of magnetic hyperfine field with increase in x.

Effects of Oxygen Stoichiometry on The Magnetic Ordering of La2Ni1-YCuY04+δ

1989 ◽  
Vol 169 ◽  
Author(s):  
J. Zhao ◽  
V. Suresh Babu ◽  
Mohindar S. Seehra ◽  
Aloysius F. Hepp ◽  
James R. Gaier ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Thermogravimetric Analysis ◽  
Oxygen Content ◽  
Magnetic Ordering ◽  
Oxygen Stoichiometry ◽  
X Ray Diffraction ◽  
Cu Doping ◽  
X Ray

AbstractAnnealing and quenching experiments in a thermogravimetric analysis apparatus are used to vary the oxygen content in La2Ni1‐yCuy04+δ, followed by magnetic susceptibility and x‐ray diffraction experiments. These studies show that for certain δ, transition to antiferromagnetism occurs with TN < 20 K. The effect of Cu doping (y = 0.01 and 0.05) on TN is negligible.

From REZnSn to REZnSnH1:5 (RE = Pr, Nd) – Inducing Ferromagnetism through Hydrogenation

2013 ◽  
Vol 68 (11) ◽  
pp. 1191-1197 ◽  
Author(s):  
Bastian Reker ◽  
Bernard Chevalier ◽  
Oliver Niehaus ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Induction Melting ◽  
Stacking Sequence ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Free Ion

The ternary stannides PrZnSn and NdZnSn were synthesized by induction-melting of the elements in sealed tantalum tubes. They were characterized by powder and single-crystal X-ray diffraction: YPtAs-type structure, P63=mmc, a = 455:4(1) and c = 1650:3(2) pm, wR2=0.0266, 297 F2 for PrZnSn and a = 453:7(1) and c = 1637:0(4) pm, wR2=0.1558, 234 F2 for NdZnSn with 12 variables per refinement. PrZnSn and NdZnSn are AlB2 superstructures with slightly puckered and ordered [Zn3Sn3] hexagons in AA´BB´ stacking sequence along the crystallographic c axis. Hydrogenation results in the new hexagonal hydrides PrZnSnH1:5 (a = 447:98(8) and c = 1707:5(5) pm) and NdZnSnH1:5 (a = 448:28(8) and c = 1689:8(2) pm). Filling of RE3Zn tetrahedra by hydrogen leads to anisotropic changes of the lattice parameters and a drastic flattening of the [Zn3Sn3] layers. Temperature-dependent magnetic susceptibility measurements show Curie-Weiss behavior for PrZnSn and NdZnSn with experimental magnetic moments close to the free-ion values of RE3+. Magnetic ordering is detected at 4.7 (PrZnSn) and 6:5 K (NdZnSn). Hydrogenation induces ferromagnetism with increased ordering temperatures of 12.0 (PrZnSnH1:5) and 14:5 K (NdZnSnH1:5).

STRUCTURAL AND MAGNETOELASTIC PROPERTIES OF Y3Fe27.2Cr1.8 AND Ce3Fe25Cr4 FERROMAGNETIC COMPOUNDS

2011 ◽  
Vol 25 (24) ◽  
pp. 1949-1961 ◽  
Author(s):  
N. TAJABOR ◽  
A. GHOLIZADEH ◽  
M. BEHDANI ◽  
D. SANAVI KHOSHNOUD ◽  
H. SALAMATI ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Linear Thermal Expansion Coefficient ◽  
Ac Susceptibility ◽  
Linear Thermal Expansion ◽  
Magnetic Ordering ◽  
Anisotropy Field ◽  
Magnetic Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetoelastic Properties

The structural and magnetoelastic properties of polycrystalline samples of Y 3 Fe 27.2 Cr 1.8 and Ce 3 Fe 25 Cr 4 intermetallic compounds are investigated by means of X-ray diffraction, thermomagnetic, thermal expansion and magnetostriction measurements in the temperature range of 77–500 K under applied magnetic fields up to 1.5 T. The well defined anomalies observed in the linear thermal expansion coefficient curves are associated with the magnetic phase transitions and presence of small amounts of 1:12 phase in the Ce 3 Fe 25 Cr 4 sample; the latter is also confirmed by AC susceptibility measurements. For Y 3 Fe 27.2 Cr 1.8, saturation behavior is observed in the anisotropic magnetostriction isotherms near the magnetic ordering temperature (TC), whereas for Ce 3 Fe 25 Cr 4 compound, saturation starts well below TC. The additional anomalies observed in the volume magnetostriction isotherms of both compounds are explained based on the anisotropy field in the a–b plane and along the c-axis of the unit cell.

SUPERCONDUCTIVITY IN Bi-Sr-Ca-Mg-Cu-OXIDE

1991 ◽  
Vol 05 (11) ◽  
pp. 771-777 ◽  
Author(s):  
A.Y. KHAN ◽  
M. MOHAMMAD ◽  
M. SHAHNAZ ◽  
S.K. HASNAIN
Keyword(s):  
Magnetic Susceptibility ◽  
Electrical Resistance ◽  
Meissner Effect ◽  
Superconducting Phase ◽  
Partial Substitution ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Minor Phase ◽  
X Ray ◽  
A Minor

A Mg -substituted material with nominal composition Bi 2 Sr 2 Ca 3 Mg 2 Cu 6 O x, prepared by partial substitution of Ca by isovalent Mg in the 2256 composition of Bi-Sr-Ca-Cu-O , has been studied by the measurements of electrical resistance, magnetic susceptibility and X-ray diffraction pattern. Results show the existence of a superconducting phase with onset T c at 112.5±1 K along with a minor phase with onset T c =88 K . The material retained superconducting characteristics (Meissner effect and T c onset ) even after a period of six months.

Synthesis and Structure of Some MII/MIII Mixed Fluorides with Pyrochlore and Weberite Related Structures

2006 ◽  
Vol 61 (7) ◽  
pp. 808-812 ◽  
Author(s):  
M. A. Subramanian ◽  
W. J. Marshall ◽  
R.-D. Hoffmann ◽  
A.W. Sleight
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Susceptibility ◽  
Single Crystals ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Antiferromagnetic Ordering

New NH4MIIMIIIF6 and MIIMIIIF5 ・ 2H2O compounds with the pyrochlore and weberite structures, respectively, are reported. Structures of NH4CoCrF6, AlZnF5 ・ 2H2O, and GaMnF5 ・ 2H2O were refined using X-ray diffraction data from single crystals. The structures of MgIIAlIIIF5 ・H2O and NH4MgIIAlIIIF6 were refined from powder X-ray diffraction data. Magnetic susceptibility data indicates antiferromagnetic ordering in NH4CoIIVIIIF6 at 7 K but no ordering in NH4CoIICrIIIF6 down to 4.2 K. Electrical conductivity presumably due to protons was observed in MgAlF5 ・ (H2O)2.

scholarly journals X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84 ◽  
Author(s):  
Satoru Urakawa ◽  
Toru Inoue ◽  
Takanori Hattori ◽  
Asami Sano-Furukawa ◽  
Shinji Kohara ◽  
...  
Keyword(s):  
Oxide Glasses ◽  
Void Space ◽  
X Ray Diffraction ◽  
Amorphous Sio2 ◽  
Sio2 Glass ◽  
X Ray ◽  
X Ray Scattering ◽  
Medium Range ◽  
Two Phases ◽  
A Minor

The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 Å. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si–OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra.

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