Susceptibility and Evidences of Charge Carriers Interaction above Tc in Nd1.85Ce0.15CuO4+δ

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1151-1156 ◽  
Author(s):  
A. Lascialfari ◽  
P. Ghigna ◽  
S. De Gennaro
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Critical Temperature ◽  
Charge Carrier ◽  
Effective Magnetic Moment ◽  
Carrier Density ◽  
Charge Carriers ◽  
Oxide Superconductors ◽  
Charge Carrier Density ◽  
Copper Oxide Superconductors

The charge carrier density plays a crucial role in the transition between normal and superconducting state in the copper-oxide superconductors. In Nd 1.85 Ce 0.15 CuO 4+δ sample, for charge carrier density n = nc≃ 0.07 the superconductivity sets in. In order to investigate the magnetic properties around nc, a set of magnetic susceptibility measurements in the temperature range 3-260K for samples with different charge carriers concentrations were realized. Magnetic susceptibility curves of Nd 1.85 Ce 0.15 CuO 4+δ revealed novel behavior well above the critical temperature T c: at fixed T ≥45 K , the susceptibility χ, reported as a function of the charge carrier density n, shows a peak around n=0.06 and drops to significantly lower values for n greater than 0.07, the value at which the samples become superconducting. The effective magnetic moment μeff shows the same behavior. The comparison of the present experimental results with recent transport ones gives evidence of a possible interaction between charge carriers above T c. The possibility that this effect could be due to a bipolarons-like mechanism of charge carriers interaction is discussed.

Charge-Transport in Partially-Ordered Regioregular Poly(3-Hexylthiophene) Studied as a Function of the Charge-carrier Density

2000 ◽  
Vol 660 ◽  
Author(s):  
D.B.A. Rep ◽  
B.-H. Huisman ◽  
E.J. Meijer ◽  
P. Prins ◽  
T.M. Klapwijk
Keyword(s):  
Charge Carrier ◽  
Charge Transport ◽  
Conjugated Polymer ◽  
Carrier Density ◽  
Structural Changes ◽  
Charge Carriers ◽  
Charge Carrier Density ◽  
Partially Ordered ◽  
Regioregular Poly

ABSTRACTWe demonstrate that charge-transport in partially-ordered thin films of poly(3- hexylthiophene) is strongly dependent on the charge-carrier density in the film, which we relate to the localized nature of the charge carriers. We base our conclusions on measurements in which the charge-carrier density is varied by electrostatic means (in a transistor geometry) and by in- situ thermal removal of oxygen dopants. For the doping levels investigated, we argue that the removal of oxygen does not induce structural changes in the conjugated polymer, and that it only shifts the Fermi-level of the film.

Superconductivity Above 77 K in the Cubic Ba2Ycu2Wo9-Y Oxide System

1989 ◽  
Vol 169 ◽  
Author(s):  
Bokhimi ◽  
A. Garcia-Ruiz
Keyword(s):  
Charge Carrier ◽  
Carrier Density ◽  
Meissner Effect ◽  
Oxide System ◽  
Oxide Superconductors ◽  
Charge Carrier Density ◽  
Correct Interpretation ◽  
Experimental Conditions ◽  
New Family ◽  
Cubic Structure

AbstractWe have obtained a new family of oxide superconductors, which are characterized by a cubic structure with the space group Fm3m and transition temperatures to the superconducting state above 77 K. As prototype of this family, we have studied some properties of the Ba2YCu2WO9‐y system. We report details about the experimental conditions that are necessary in order to obtain the cubic structure and to change the charge carrier density. The samples show superconducting behavior around 90 K with only a small Meissner effect fraction. These results can be interpreted in terms of filamentary superconductivity, however, it is necessary to characterize the system further to give a correct interpretation of the results.

scholarly journals Temperature Dependence of Electronic and Magnetic Properties of (DOEO)4[HgBr4]·TCE Single Crystals

2015 ◽  
Vol 233-234 ◽  
pp. 173-176
Author(s):  
Alisa Chernenkaya ◽  
Oksana Koplak ◽  
Katerina Medjanik ◽  
Aleksandr Kotov ◽  
Roman Morgunov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Ground State ◽  
Carrier Density ◽  
Charge Carrier Density ◽  
Pronounced Increase ◽  
Electronic And Magnetic Properties ◽  
Increasing Temperature ◽  
Semiconducting Behavior

The temperature dependence of electronic and magnetic properties of the organic charge-transfer salt (DOEO)4[HgBr4]·TCE was investigated using magnetometry. The magnetic susceptibility shows a maximum at 40 K followed by an onset of a pronounced increase at 70 K and a constant behavior above 120 K. Implications on the charge carrier density are discussed. Combining the magnetometry with resistivity and ESR measurements we propose a sequence of insulating, metallic and semiconducting behavior with increasing temperature. Our results indicate that (DOEO)4[HgBr4]·TCE is close to the boundary between an insulating and conducting ground state.

scholarly journals The effect of atmospheric doping on pressure-dependent Raman scattering in supported graphene

2018 ◽  
Vol 9 ◽  
pp. 704-710 ◽  
Author(s):  
Egor A Kolesov ◽  
Mikhail S Tivanov ◽  
Olga V Korolik ◽  
Olesya O Kapitanova ◽  
Xiao Fu ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Raman Scattering ◽  
Carrier Density ◽  
Opposite Effect ◽  
Substrate Material ◽  
Charge Carriers ◽  
Charge Carrier Density ◽  
Electron Charge ◽  
Nanoelectronic Devices ◽  
Phonon Properties

Atmospheric doping of supported graphene was investigated by Raman scattering under different pressures. Various Raman spectra parameters were found to depend on the pressure and the substrate material. The results are interpreted in terms of atmospheric adsorption leading to a change in graphene charge carrier density and the effect of the substrate on the electronic and phonon properties of graphene. It was found that adsorption of molecules from the atmosphere onto graphene doped with nitrogen (electron doping) compensates for the electron charge. Furthermore, the atmosphere-induced doping drastically decreases the spatial heterogeneity of charge carriers in graphene doped with nitrogen, while the opposite effect was observed for undoped samples. The results of this study should be taken into account for the development of sensors and nanoelectronic devices based on graphene.

Thermal Frequency Imaging: A New Application of Laser Voltage Imaging Applied on 40nm Technology

2011 ◽  
Author(s):  
Guillaume Celi ◽  
Sylvain Dudit ◽  
Thierry Parrassin ◽  
Philippe Perdu ◽  
Antoine Reverdy ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Laser Beam ◽  
Integrated Circuit ◽  
Carrier Density ◽  
Deep Submicron ◽  
Charge Carrier Density ◽  
Voltage Imaging ◽  
A New Technique ◽  
Scan Chain

Abstract For Very Deep submicron Technologies, techniques based on the analysis of reflected laser beam properties are widely used. The Laser Voltage Imaging (LVI) technique, introduced in 2009, allows mapping frequencies through the backside of integrated circuit. In this paper, we propose a new technique based on the LVI technique to debug a scan chain related issue. We describe the method to use LVI, usually dedicated to frequency mapping of digital active parts, in a way that enables localization of resistive leakage. Origin of this signal is investigated on a 40nm case study. This signal can be properly understood when two different effects, charge carrier density variations (LVI) and thermo reflectance effect (Thermal Frequency Imaging, TFI), are taken into account.

Suppression of Ferromagnetism in EuxCa1-xB6

2012 ◽  
Vol 190 ◽  
pp. 97-100 ◽  
Author(s):  
V.V. Glushkov ◽  
A.V. Kuznetsov ◽  
I. Sannikov ◽  
A.V. Bogach ◽  
S.V. Demishev ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Curie Temperature ◽  
Single Crystals ◽  
Effective Magnetic Moment ◽  
Paramagnetic State ◽  
Low Field ◽  
Wide Range ◽  
Free Ion ◽  
The Eu

We report the magnetic properties of EuxCa1-xB6 single crystals (0.756x1) studied in the wide range of temperatures (1.8-300 K) and magnetic fields (up to 50 kOe). It was found that low field magnetic susceptibility χ (T) follows the Curie-Weiss law χ~(T-Θp)-1 at high temperatures for all the concentrations studied. The effective magnetic moment of the Eu2+ ion estimated from the data diminishes from the free ion value μeff7.93μB (μB - Bohr magneton) for x=1 to μeff7.3μB for x=0.756. A universal behavior of magnetic susceptibility χ~(T-Θ)-α (α=1.5) is detected close to the Curie temperature TC in the paramagnetic state at both metallic (x>xC~0.8) and dielectric (xC.

scholarly journals Zn2+ Ion Surface Enrichment in Doped Iron Oxide Nanoparticles Leads to Charge Carrier Density Enhancement

ACS Omega ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 16328-16337 ◽  
Author(s):  
Stanley Bram ◽  
Matthew N. Gordon ◽  
Michael A. Carbonell ◽  
Maren Pink ◽  
Barry D. Stein ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Charge Carrier ◽  
Iron Oxide Nanoparticles ◽  
Carrier Density ◽  
Oxide Nanoparticles ◽  
Charge Carrier Density ◽  
Surface Enrichment ◽  
Density Enhancement

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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