scholarly journals Potassium-Doped Para-Terphenyl: Structure, Electrical Transport Properties and Possible Signatures of a Superconducting Transition

2020 ◽  
Vol 5 (4) ◽  
pp. 78
Author(s):  
Nicola Pinto ◽  
Corrado Di Nicola ◽  
Angela Trapananti ◽  
Marco Minicucci ◽  
Andrea Di Cicco ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Chemical Method ◽  
Preliminary Evidence ◽  
Superconducting Gap ◽  
Superconducting Transition ◽  
Electrical Transport Properties ◽  
High Tc ◽  
Resistivity Measurements

Preliminary evidence for the occurrence of high-TC superconductivity in alkali-doped organic materials, such as potassium-doped p-terphenyl (KPT), were recently obtained by magnetic susceptibility measurements and by the opening of a large superconducting gap as measured by ARPES and STM techniques. In this work, KPT samples have been synthesized by a chemical method and characterized by low-temperature Raman scattering and resistivity measurements. Here, we report the occurrence of a resistivity drop of more than 4 orders of magnitude at low temperatures in KPT samples in the form of compressed powder. This fact was interpreted as a possible sign of a broad superconducting transition taking place below 90 K in granular KPT. The granular nature of the KPT system appears to be also related to the 20 K broadening of the resistivity drop around the critical temperature.

scholarly journals Magnetic and Electrical Transport Properties of Vanadium Telluride

1980 ◽  
Vol 35 (7) ◽  
pp. 701-703 ◽  
Author(s):  
C. Prasad ◽  
R. A. Singh
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Magnetic Susceptibility ◽  
Electrical Transport ◽  
Powdered Sample ◽  
Neel Temperature ◽  
Electrical Transport Properties ◽  
Néel Temperature ◽  
Paramagnetic Curie Temperature ◽  
Temperature Range

Measurements of the magnetic susceptibility of a powdered sample of VTe in the temperature range 90 - 700 K, and of the a.c. electrical conductivity (σ), thermoelectric power (θ) and dielectric constant (ε′) of pressed pellets of the compound in the temperature range 300 -1100 K are reported. The compound is found to be antiferromagnetic with Neel temperature 420 ± 5 K. The effective paramagnetic moment and paramagnetic Curie temperature are found to be 1.6 μB and - 250 K, respectively. The dependence of σ, θ and ε′ on temperature shows no anomaly at the Neel temperature and is indicative of the metallic nature of the compound.

Magnetic and electrical transport properties of Sr2Ti1−xCoxO4 ceramics by sol–gel

2017 ◽  
Vol 31 (17) ◽  
pp. 1750195
Author(s):  
Li Zhang ◽  
Yibao Li ◽  
Zhen Tang ◽  
Yan Deng ◽  
Hui Yuan ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
Sol Gel ◽  
Variable Range Hopping ◽  
Electrical Transport Properties ◽  
Co Doping ◽  
Hopping Model ◽  
Variable Range Hopping Model ◽  
Co Doped

Microstructures, electrical transport and magnetic properties of Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics are investigated. With Co doping, the Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics remain tetragonal structure while the grain size is decreased with doping. Magnetic moment is enhanced with Co doping and ferromagnetism is observed at low temperatures for Co-doped Sr[Formula: see text]TiO[Formula: see text]. The Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] and Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] show semiconductor-like transport properties, which can be well fitted by Mott variable range hopping model. The results will provide an effective route to synthesize Sr[Formula: see text]Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ceramics as well as to investigate the physical properties.

Structural and electrical transport properties of FeHxunder high pressures and low temperatures

2011 ◽  
Vol 31 (1) ◽  
pp. 64-67 ◽  
Author(s):  
Takahiro Matsuoka ◽  
Naohisa Hirao ◽  
Yasuo Ohishi ◽  
Katsuya Shimizu ◽  
Akihiko Machida ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Low Temperatures ◽  
High Pressures ◽  
Electrical Transport Properties

scholarly journals High Jc and low anisotropy of hydrogen doped NdFeAsO superconducting thin film

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazumasa Iida ◽  
Jens Hänisch ◽  
Keisuke Kondo ◽  
Mingyu Chen ◽  
Takafumi Hatano ◽  
...  
Keyword(s):  
Thin Film ◽  
Electrical Transport ◽  
Epitaxial Thin Films ◽  
Superconducting Transition ◽  
Electrical Transport Properties ◽  
Superconducting Thin Film ◽  
Ginzburg Landau ◽  
Microscopy Investigation ◽  
Scaling Parameters ◽  
Hydrogen Substitution

AbstractThe recent realisations of hydrogen doped LnFeAsO (Ln = Nd and Sm) superconducting epitaxial thin films call for further investigation of their structural and electrical transport properties. Here, we report on the microstructure of a NdFeAs(O,H) epitaxial thin film and its temperature, field, and orientation dependencies of the resistivity and the critical current density Jc. The superconducting transition temperature Tc is comparable to NdFeAs(O,F). Transmission electron microscopy investigation supported that hydrogen is homogenously substituted for oxygen. A high self-field Jc of over 10 MA/cm2 was recorded at 5 K, which is likely to be caused by a short London penetration depth. The anisotropic Ginzburg–Landau scaling for the angle dependence of Jc yielded temperature-dependent scaling parameters γJ that decreased from 1.6 at 30 K to 1.3 at 5 K. This is opposite to the behaviour of NdFeAs(O,F). Additionally, γJ of NdFeAs(O,H) is smaller than that of NdFeAs(O,F). Our results indicate that heavily electron doping by means of hydrogen substitution for oxygen in LnFeAsO is highly beneficial for achieving high Jc with low anisotropy without compromising Tc, which is favourable for high-field magnet applications.

Effect of sintering periods on the microstructure and electrical transport properties of high-Tc superconducting Bi–(Pb)–Sr–Ca–Cu–O tapes

1996 ◽  
Vol 11 (5) ◽  
pp. 1101-1107 ◽  
Author(s):  
N. V. Vo ◽  
H. K. Liu ◽  
S. X. Dou
Keyword(s):  
Critical Current Density ◽  
Transport Properties ◽  
Grain Growth ◽  
Electrical Transport ◽  
Critical Currents ◽  
Electrical Transport Properties ◽  
High Tc ◽  
Grain Alignment ◽  
The Core ◽  
Silver Matrix

The effect of sintering periods for monocore (Bi, Pb)2Sr2Ca2Cu3O10+x (Bi-2223) tapes on microstructure and critical current density (Jc) have been studied. The results show that long sintering periods (of duration ≥100 h) give better grain growth, but greater misalignment. Prolonged sintering also necessitates the increase in porosity of the core due to random grain growth, increasing the chance of penetrating into the silver matrix and oxide core interface. Critical currents for long sintering periods are found to be lower in comparison with those obtained for slightly shorter sintering periods. The increase in frequency of intermediate cold uniaxial pressing between sintering periods assists grain alignment. However, when the sintering period is further reduced by increasing the frequency of intermediate deformation, it is found that microcracks are unable to heal as there is not enough time for grain regrowth. The tapes made using “three-to-four-sinter-period” (each period ∼60 h) show superior electrical transport properties which are attributable to the fact that their oxide core is more dense and better aligned relative to the “two-sinter-period” (each period ≥100 h) tapes and contain less cracks relative to the “five-to-six-sinter-period” (each period ∼40 h) tapes.

scholarly journals Magnetic Susceptibility of Quasi-two-dimensional Cuprate Antiferromagnets

2013 ◽  
Vol 37 (1) ◽  
pp. 19-32
Author(s):  
Milica S. Rutonjski ◽  
Milan R. Pantić ◽  
Slobodan M. Radošević ◽  
Milica V. Pavkov-Hrvojević
Keyword(s):  
Magnetic Susceptibility ◽  
Low Temperatures ◽  
Parent Compound ◽  
Random Phase ◽  
Mean Field ◽  
Three Dimensional ◽  
Quantum Spin ◽  
Spin Fluctuations ◽  
High Tc ◽  
Lsw Theory

Abstract Parallel magnetic susceptibility temperature dependence of the high-TC superconducting parent compound La2CuO4 is calculated in both antiferromagnetic (AFM) and paramagnetic phase. By making use of the quantum Heisenberg three-dimensional AFM model including the in-plane spin anisotropy, the calculation is performed within the framework of three different theories: Green’s function theory in random-phase approximation (RPA), linear spinwave (LSW) theory and mean-field (MF) theory. The results suggest that at low temperatures quantum spin fluctuations play an important role, while at the temperatures above the critical one short-range correlations have a great impact on the behavior of the system. This leads to the discrepancy between RPA and MF results, since the later neglects the above phenomena. Further, LSW theory expectedly agrees with RPA results only at low temperatures where the magnon interactions are negligible. Comparison to the theoretical and experimental results quoted in literature confirms that RPA method presents the most appropriate method among the applied ones, suggesting that this approach is satisfactory in the case of the parallel magnetic susceptibility, while in order to reproduce the transversal one, spin-orbit coupling must be included.

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