HIGH-TEMPERATURE OXIDE SUPERCONDUCTORS: STRUCTURE, STOICHIOMETRY AND THE MECHANISM OF SUPERCONDUCTIVITY

1987 ◽  
Vol 01 (03n04) ◽  
pp. 721-732 ◽  
Author(s):  
C.N.R. RAO
Keyword(s):  
Magnetic Susceptibility ◽  
Spectroscopic Studies ◽  
Oxide Superconductors ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
High Temperature Oxide ◽  
Temperature Oxide ◽  
Mechanism Of Superconductivity ◽  
Superconducting Oxides

Magnetic susceptibility data show La2CuO4 to be antiferromagnetic. Oxides of the K2NiF4 structure of the general formula (La1−y Lny)2−x Srx(Bax)CuO4 show superconductivity in the 15-40K range, the Tc becoming maximum at a specific value of x or of the a-parameter. Superconductivity in La3−xBa3+xCu6O14 and La4−xBa1+xCu5O13 systems has been investigated besides that in the Y-Ba-Cu-O system. Role of oxygen in the superconductivity of YBa2Cu3O7−δ is discussed. The problem of rationalizing macro and microstructures of YBa2Cu3O7−δ is indicated. Infrared spectra of the superconducting oxides and their marginal metallicity in the normal state are examined. Based on electron spectroscopic studies, it is shown that holes are likely to be on oxygen rather than on copper, giving rise to peroxide-like species; Copper is present in the 1+ state (besides the 2+ state).

EPR AND MAGNETIC SUSCEPTIBILITY STUDIES OF Gd3+ IONS-DOPED BISMUTH–GERMANATE GLASS MATRIX

2008 ◽  
Vol 22 (06) ◽  
pp. 447-453 ◽  
Author(s):  
P. PASCUTA ◽  
M. BOSCA ◽  
M. CULEA ◽  
S. SIMON ◽  
E. CULEA
Keyword(s):  
Magnetic Susceptibility ◽  
Glass Matrix ◽  
Paramagnetic Resonance ◽  
Germanate Glass ◽  
Magnetic Susceptibility Data ◽  
Crystalline Field ◽  
Susceptibility Data ◽  
Host Glass ◽  
Electron Paramagnetic

Glasses of the x Gd 2 O 3 · (100-x)[4 Bi 2 O 3 · GeO 2] system, with 1 ≤ x ≤ 30 mol% were obtained and investigated by electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. The EPR spectra of the studied glasses reveal resonance sites with an unexpected high crystalline field in addition to the "U" spectrum, typical for Gd 3+ ions in glasses. This absorption line is due to Gd 3+ ions that replace Bi 3+ ions from the host glass matrix and can play former role of the unconventional network in the studied glasses. EPR and magnetic susceptibility data show that for low Gd 2 O 3 content, x ≤ 10 mol%, the Gd 3+ ions are randomly distributed in the host glass matrix and are present only as isolated species. For higher Gd 2 O 3 content, x > 10 mol%, the Gd 3+ ions appear as both isolated and antiferromagnetically coupled species.

scholarly journals Collective Magnetic Behavior of 11 nm Photo-Switchable CsCoFe Prussian Blue Analogue Nanocrystals: Effect of Dilution and Light Intensity

2021 ◽  
Vol 7 (7) ◽  
pp. 99
Author(s):  
Linh Trinh ◽  
Eric Rivière ◽  
Sandra Mazerat ◽  
Laure Catala ◽  
Talal Mallah
Keyword(s):  
Magnetic Susceptibility ◽  
Light Intensity ◽  
Prussian Blue ◽  
Magnetic Behavior ◽  
Magnetic Interaction ◽  
Light Irradiation ◽  
Prussian Blue Analogue ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data

The collective magnetic behavior of photoswitchable 11 nm cyanide-bridged nanoparticles based of the Prussian blue analogue CsCoFe were investigated when embedded in two different matrices with different concentrations. The effect of the intensity of light irradiation was studied in the less concentrated sample. Magnetization studies and alternating magnetic susceptibility data are consistent with a collective magnetic behavior due to interparticle dipolar magnetic interaction for the two compounds, even though the objects have a size that place them in the superparamagnetic regime.

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.

NEUTRON POWDER DIFFRACTION AND OXIDE SUPERCONDUCTORS

1993 ◽  
Vol 07 (16n17) ◽  
pp. 3077-3093 ◽  
Author(s):  
A.W. HEWAT
Keyword(s):  
Heavy Metals ◽  
High Temperature ◽  
Powder Diffraction ◽  
Neutron Powder Diffraction ◽  
Oxide Superconductors ◽  
X Rays ◽  
New Materials ◽  
Oxidation Reduction ◽  
High Temperature Oxide ◽  
Temperature Oxide

Neutron powder diffraction has been essential for understanding the structures of the new high temperature oxide superconductors because of the difficulty in locating oxygen with X-rays in the presence of heavy metals, especially when single crystals are usually not available. This understanding lead to the discovery of new materials. In this paper we will show how it also sheds light on the crystal chemistry of oxide superconductors—the effects of oxidation/reduction, phase separation, pressure etc.

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