THE EFFECT OF PARTIAL ATOMIC SUBSTITUTION ON ELECTRIC AND MAGNETIC PROPERTIES OF (Bi,Pb):2223 SINTERED SUPERCONDUCTORS

2003 ◽  
Vol 17 (26) ◽  
pp. 4675-4681 ◽  
Author(s):  
A. V. POP ◽  
M. POP ◽  
I. I. GERU
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Electrical Resistance ◽  
Ac Susceptibility ◽  
Partial Substitution ◽  
Superconducting Transition ◽  
Ac Magnetic Susceptibility ◽  
Atomic Concentration ◽  
Susceptibility Data ◽  
Atomic Substitution

The effect of partial substitution of Ca by x = 0.02 La on the electrical and magnetically properties of two (Bi,Pb):2223 superconductor ceramic S1 and S2 (with different Pb and Sr atomic concentration) were investigated by using electrical resistance and AC magnetic susceptibility measurements. The parameters from linear resistivity data in the normal state and superconducting transition are sensitive to the compounds stoechiomerty. The intergrain critical current density JcJ(T) dependence near Tc obtained from immaginary AC susceptibility data agrees with the assumption of SNS intergrain junctions.

The Effect of Partial Substitution of Non-Magnetic Impurity Zn on the Magnetic Moments of Eu1.88Ce0.12Cu1-yZnyO4+α-δ

2021 ◽  
Vol 1028 ◽  
pp. 15-20
Author(s):  
Muhammad Abdan Syakuur ◽  
Yati Maryati ◽  
Togar Saragi ◽  
Risdiana
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Impurity ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Partial Substitution ◽  
X Ray Diffraction ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Volume Unit

Structure and magnetic properties of electron-doped superconducting cuprates have been investigated in order to study the effect of magnetic impurity to its physical properties. Here, we reported structure and magnetic properties of Eu1.88Ce0.12Cu1-yZnyO4+α-δ (ECCZO) with y = 0 and 0.03. The properties of ECCZO have been studied from X-ray diffraction data and temperature dependence of magnetic susceptibility data, to elucidate the effect of partial substitution of non-magnetic impurity Zn for Cu to its structure, Tc and the value of magnetic moments per unit volume extracted from susceptibility data in normal state. Magnetic-susceptibility measurements were carried out down to 2 K on-field cooling at 5 Oe for Eu1.88Ce0.12Cu1-yZnyO4+a-d with y = 0 and 0.03. For ECCZO sample with y = 0 and d = 0.0669 indicated the change of magnetic behavior from paramagnetic to diamagnetic below 12 K which is addressed to the Tc onset of this samples. Diamagnetic behavior is observed starting from about 12 K. Above 12 K, all samples show paramagnetic behavior with the values of the magnetic moment in every volume unit increased with increasing Zn.

scholarly journals Incompatibility of Published ac Magnetic Susceptibility of a Room Temperature Superconductor with Measured Raw Data

2021 ◽  
Author(s):  
J. E. Hirsch
Keyword(s):  
High Pressure ◽  
Magnetic Susceptibility ◽  
Room Temperature ◽  
Superconducting Transition ◽  
Ac Magnetic Susceptibility ◽  
Raw Data ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Room Temperature Superconductivity

Room temperature superconductivity has recently been reported for a carbonaceous sulfur hydride (CSH) under high pressure by Snider et al [1]. The paper reports sharp drops in magnetic susceptibility as a function of temperature for five different pressures, that are interpreted as signaling a superconducting transition. Here I question the validity and faithfulness of the magnetic susceptibility data presented in the paper by comparison with the measured raw data reported by two of the authors of ref. [2]. This invalidates the assertion of the paper [1] that the susceptibility measurements support the case for superconductivity in this compound.

On the Effect of Nanocrystallization and Disorder on the Magnetic Properties of Cu-Rich, FeMnCu Alloys

2007 ◽  
Vol 7 (2) ◽  
pp. 610-617
Author(s):  
S. J. Stewart ◽  
J. F. Marco ◽  
P. Crespo ◽  
J. J. Romero ◽  
A. Martínez ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
The Other ◽  
Ac Magnetic Susceptibility ◽  
Pure Element ◽  
Enthalpies Of Mixing ◽  
Mossbauer Spectra ◽  
Susceptibility Data ◽  
Basic Characteristics ◽  
The One

We report on the temperature dependencies of the Mössbauer spectra and the AC magnetic susceptibility measured in Cu-rich, FeMnCu samples prepared by mechanically alloying, using, on the one side, Cu and prealloyed FeMn powders and, on the other, pure element Cu, Mn, and Fe powders. From the correlation of the Mössbauer and susceptibility data we conclude about the basic characteristics of the phase distributions present in the different studied samples. Those distributions are a consequence of both the nanostructure induced upon milling and of the different signs of the Mn/Cu (negative) and Fe/Cu (positive) enthalpies of mixing. The proposed phase distributions are significantly different in the samples prepared from different precursors and this fact is analyzed in terms of the disproportion of the precursor FeMn alloy and in those of the favoured Mn/Cu interdiffusion and the hindered Fe/Cu one.

scholarly journals Incompatibility of Published ac Magnetic Susceptibility of a Room Temperature Superconductor with Measured Raw Data

2021 ◽  
Author(s):  
Jorge Hirsch
Keyword(s):  
High Pressure ◽  
Magnetic Susceptibility ◽  
Room Temperature ◽  
Superconducting Transition ◽  
Ac Magnetic Susceptibility ◽  
Raw Data ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Room Temperature Superconductivity

Room temperature superconductivity has recently been reported for a carbonaceous sulfur hydride (CSH) under high pressure by Snider et al [1]. The paper reports sharp drops in magnetic susceptibility as a function of temperature for five different pressures, that are interpreted as signaling a superconducting transition. Here I question the validity and faithfulness of the magnetic susceptibility data presented in the paper by comparison with the measured raw data reported by two of the authors of ref. [2]. This casts doubt on the assertion of the paper [1] that the susceptibility measurements support the case for superconductivity in this compound.

scholarly journals Transition metals in ZnO nanocrystals: Magnetic and structural properties

2013 ◽  
Vol 45 (1) ◽  
pp. 31-48 ◽  
Author(s):  
I. Kuryliszyn-Kudelska ◽  
W. Dobrowolski ◽  
M. Arciszewska ◽  
N. Romcevic ◽  
M. Romcevic ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Ac Susceptibility ◽  
Peak Temperature ◽  
Blocking Temperature ◽  
Ac Magnetic Susceptibility ◽  
Ion Content ◽  
Superparamagnetic Behavior ◽  
Zno Nanocrystals ◽  
Magnetic Ion

Currently, wide-gap ZnO nanoparticles bear important potential application in electro-optical devices, transparent ultraviolet protection films, and spintronic devices. We have studied the magnetic properties of nanocrystals of ZnO(Fe, Co, Mn) prepared by two methods of synthesis. We have used the microwave assisted hydrothermal synthesis and traditional wet chemistry method followed by calcination. The detailed structural characterization was performed by means of X-ray diffraction and micro-Raman spectroscopy measurements. The morphology of the samples was studied by means of SEM and TEM microscopy. The results of systematic measurements of AC magnetic susceptibility as a function of temperature and frequency as well as SQUID magnetization are presented. The SQUID magnetization measurements revealed a clear bifurcation of the FC and ZFC plots. Such behavior suggested superparamagnetic behavior above the blocking temperature. The dynamic magnetic measurements were performed at small AC magnetic field with amplitude not exceeding 5 Oe and different frequency values (from 7 Hz to 9970 Hz). For ZnO(Fe) and ZnO(Mn), the AC susceptibility maxima has been found for in-phase susceptibility Re(?) and for out of phase susceptibility Im(?). We analyzed the observed frequency dependence of the peak temperature in the AC susceptibility curve using the empirical parameter ? that is a quantitative measure of the frequency shift and is given by the relative shift of the peak temperature per decade shift in frequency, as well as Vogel- Fulcher law. We observed two different types of magnetic behavior, spin-glasslike behavior or superparamagnetic behavior, depending on the synthesis process. For ZnO(Co) nanocrystalline samples high temperature Curie-Weiss behavior in AC magnetic susceptibility was observed. We observed that the determined negative values of the Curie- Weiss temperature ? depend strongly on the nominal content of cobalt oxide. It was shown that for calcination method the values of ? increase with the increase of magnetic ion content indicating enhancement of predominance of antiferromagnetic interactions. For hydrothermal method the opposite effect was observed indicating the breakdown of predominance of aniferromagnetic coupling with the increase of nominal magnetic ion content. This paper gives an in-depth discussion of the structural and magnetic properties of ZnO nanocrystals in addition to the technological issues such as different methods of wet chemical synthesis.

On the Effect of Nanocrystallization and Disorder on the Magnetic Properties of Cu-Rich, FeMnCu Alloys

2007 ◽  
Vol 7 (2) ◽  
pp. 610-617 ◽  
Author(s):  
S. J. Stewart ◽  
J. F. Marco ◽  
P. Crespo ◽  
J. J. Romero ◽  
A. Martínez ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
The Other ◽  
Ac Magnetic Susceptibility ◽  
Pure Element ◽  
Enthalpies Of Mixing ◽  
Mossbauer Spectra ◽  
Susceptibility Data ◽  
Basic Characteristics ◽  
The One

We report on the temperature dependencies of the Mössbauer spectra and the AC magnetic susceptibility measured in Cu-rich, FeMnCu samples prepared by mechanically alloying, using, on the one side, Cu and prealloyed FeMn powders and, on the other, pure element Cu, Mn, and Fe powders. From the correlation of the Mössbauer and susceptibility data we conclude about the basic characteristics of the phase distributions present in the different studied samples. Those distributions are a consequence of both the nanostructure induced upon milling and of the different signs of the Mn/Cu (negative) and Fe/Cu (positive) enthalpies of mixing. The proposed phase distributions are significantly different in the samples prepared from different precursors and this fact is analyzed in terms of the disproportion of the precursor FeMn alloy and in those of the favoured Mn/Cu interdiffusion and the hindered Fe/Cu one.

Magnetic Properties of Liquid Crystals Incorporating Metal Centres

1989 ◽  
Vol 175 ◽  
Author(s):  
Wolfgang Haase ◽  
Stefan Gehring ◽  
Bettina Borchers
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Liquid Crystals ◽  
Molecular Interactions ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Magnetic Effects ◽  
Diamagnetic Anisotropy

AbstractMagnetic susceptibility data (300–520 K) of monomeric and dimeric mesogenic copper(II) compounds are presented. Different magnetic effects arising from the paramagnetic Cu(II)-centres and the diamagnetic anisotropy of the mesogenic groups are observed and discussed with respect to possible inter molecular interactions.

Hydrothermal synthesis, structure and magnetic properties of a three-dimensional cobalt(ii) – aminophenyltetrazolate coordination polymer

2014 ◽  
Vol 43 (19) ◽  
pp. 7263-7268 ◽  
Author(s):  
Tiffany M. Smith ◽  
Michael Tichenor ◽  
Yuan-Zhu Zhang ◽  
Kim R. Dunbar ◽  
Jon Zubieta
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Hydrothermal Synthesis ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Magnetic Behavior ◽  
Ac Magnetic Susceptibility

The three-dimensional [Co3(OH)2(H2O)2(aptet)4] exhibits magnetic properties consistent with a ferrimagnetic chain with the non-compensating resultant moment of one Co(ii) per trinuclear Co(ii) subunit and ac magnetic susceptibility indicative of glassy-like magnetic behavior.

TIN ADDITION TO THE (Bi, Pb) 2223 SYSTEM

1994 ◽  
Vol 08 (19) ◽  
pp. 1175-1183 ◽  
Author(s):  
G. RAVI CHANDRA ◽  
B. GOPALA KRISHNA ◽  
S. V. SURYANARAYANA ◽  
T. S. N. MURTHY
Keyword(s):  
Heat Treatment ◽  
Magnetic Susceptibility ◽  
Electrical Resistance ◽  
Volume Fraction ◽  
Ac Magnetic Susceptibility ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
X Ray

The effect of the addition of Sn on the superconducting properties of the Bi 1.7 Pb 0.3 Sr 2 Ca 2 Cu 3 O y system as functions of Sn concentration and heat treatment has been studied by dc electrical resistance, ac magnetic susceptibility, and X-ray diffraction. Tin addition suppresses the volume fraction of the high T c phase. Samples with Sn > 0.1 show metallic behavior up to LNT. The formation of the Ca 2 PbO 4 phase is promoted by Sn. This depletes the amount of Pb and Ca necessary for the formation of the 2223 phase, thus reducing the volume fraction of the 2223 phase. It is possible that at least a small fraction of tin substitutes some of the cationic sites of the starting composition. The results of the different measurements are presented.

Crystal Structure and Magnetic Properties of (2,2'-Dipyridyl)-(2-acetylphenolato)copper(II) Perchlorate

2002 ◽  
Vol 57 (10) ◽  
pp. 1129-1132 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
I. Svoboda
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Moment ◽  
Basal Plane ◽  
Effective Magnetic Moment ◽  
Mixed Ligand ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Dimeric Unit

The mixed-ligand dinuclear complex (2,2'-dipyridyl)-(2-acetylphenolato)copper(II) perchlorate was synthesized and its crystal structures determined. The structure consists of a dimeric unit involving a planar Cu2O2 group. The coordination sphere of the Cu atom can be described as an alongated octahedron where the basal plane is formed by the two N atoms of the 2,2'-dipyridyl molecule and the two O atoms of the acetophenon anion. Two apical Cu - O contacts complete the 4+2 coordination of the Cu atoms. They correspond to one of the O atoms of the perchlorate anion and to the O atom of the second unit. Magnetic susceptibility data obey the Curie-Weiss law with θ = -8.1(2) K. The decreasing of the effective magnetic moment from 1.94(8) μB at 300 K to 1.86(8) μB at 70 K and the negative Weiss constant indicate weak antiferromagnetic interactions between the two copper atoms in the dimeric units.

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