ELECTRICAL RESISTIVITY OF GRAPHITE IRRADIATED WITH NEUTRONS

1957 ◽  
Vol 35 (4) ◽  
pp. 462-469
Author(s):  
R. W. Attree ◽  
O. Dahlinger
Keyword(s):  
Electrical Resistivity ◽  
Neutron Irradiation ◽  
Electrical Resistance ◽  
Electron Structure ◽  
Experimental Results ◽  
Subsequent Annealing ◽  
Artificial Graphite

Measurements have been made of the changes in the electrical resistance of an artificial graphite which are induced by neutron irradiation and subsequent annealing. The resistivity increases with irradiation; the increase in resistance is partially removed by annealing at 128 °C. These changes have been interpreted using Wallace's theory of the electron structure of graphite. The number of atoms displaced by the irradiation has been calculated using the method of Seitz, and is shown to be consistent with the experimental results.

Synthesis, Structure and Magnetism of ErCoIn5

2004 ◽  
Vol 848 ◽  
Author(s):  
Evan Lyle Thomas ◽  
Erin E. Erickson ◽  
Monica Moldovan ◽  
David P. Young ◽  
Julia Y. Chan
Keyword(s):  
Magnetic Properties ◽  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Single Crystal ◽  
Experimental Results ◽  
Flux Growth ◽  
X Ray Diffraction ◽  
Metallic Behavior ◽  
X Ray ◽  
Growth Method

AbstractA new member of the LnMIn5 family, ErCoIn5, has been synthesized by a flux-growth method. The structure of ErCoIn5 was determined by single crystal X-ray diffraction. It crystallizes in the tetragonal space group P4/mmm, Z = 1, with lattice parameters a = 4.5400(4) and c = 7.3970(7) Å, and V = 152.46(2) Å3. Electrical resistivity data show metallic behavior. Magnetic susceptibility measurements show this compound to be antiferromagnetic with TN = 5.1 K. We compare these experimental results with those of LaCoIn5 in an effort to better understand the effect of the structural trends observed on the transport and magnetic properties.

LOW TEMPERATURE RESISTIVITY OF TRANSITION ELEMENTS: VANADIUM, NIOBIUM, AND HAFNIUM

1957 ◽  
Vol 35 (8) ◽  
pp. 892-900 ◽  
Author(s):  
G. K. White ◽  
S. B. Woods
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Electrical Resistance ◽  
Thermal Resistivity ◽  
Superconducting Transition ◽  
Transition Elements ◽  
Pure Niobium ◽  
Temperature Resistivity ◽  
The Ideal

Measurements of the thermal conductivity from 2° to 90 ° K. and electrical conductivity from 2° to 300 ° K. are reported for vanadium, niobium, and hafnium. Although the vanadium and hafnium are not as pure as we might wish, measurements on these metals and on niobium allow a tabulation of the "ideal" electrical resistivity clue to thermal scattering for these elements from 300 ° K. down to about 20 ° K. Ice-point values of the "ideal" electrical resistivity are 18.3 μΩ-cm. for vanadium, 13.5 μΩ-cm. for niobium, and 29.4 μΩ-cm. for hafnium. Values for the "ideal" thermal resistivity of vanadium and niobium are deduced from the experimental results although for vanadium and more particularly for hafnium, higher purity specimens are required before a very reliable study of "ideal" thermal resistivity can be made. For the highly ductile pure niobium, the superconducting transition temperature, as determined from electrical resistance, appears to be close to 9.2 ° K.

Search for Superconductivity under Ultra-high Pressure

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3623-3625 ◽  
Author(s):  
K. Amaya ◽  
K. Shimizu ◽  
M. I. Eremets
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Electrical Resistance ◽  
Measuring Method ◽  
Experimental Results ◽  
Molecular Systems ◽  
Ultra High Pressure ◽  
Diamond Anvil ◽  
Very Low Temperature

Techniques of producing ultra-high pressure at very low temperature and measuring method of electrical resistance and magnetization of samples confirmed in the used diamond anvil ceil (DAC) are shortly described. Experimental results on simple molecular systems such as iodine, sulfur, oxygen and organic iodanil are reviewed as typical example of pressure induced superconductivity.

Electrical resistivity of coal-bearing rocks under high temperature and the detection of coal fires using electrical resistance tomography

2015 ◽  
Vol 204 (2) ◽  
pp. 1316-1331 ◽  
Author(s):  
Zhenlu Shao ◽  
Deming Wang ◽  
Yanming Wang ◽  
Xiaoxing Zhong ◽  
Xiaofei Tang ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
High Temperature ◽  
Electrical Resistance ◽  
Electrical Resistance Tomography ◽  
Coal Fires

Organization and Compaction of Composite Filler Material Using Acoustic Focusing

2017 ◽  
Author(s):  
Lauren A. Chai ◽  
Brian W. Anthony
Keyword(s):  
Electrical Resistivity ◽  
Carbon Nanofibers ◽  
Electrical Resistance ◽  
Volume Fraction ◽  
Acoustic Radiation ◽  
Mineral Oil ◽  
Acoustic Focusing ◽  
Initial Drop ◽  
Light Mineral ◽  
External Face

Carbon nanofibers in polymer-based composites reduce the electrical resistivity of the composite but can be up to 100 times more expensive than the bulk polymer. This work uses acoustic focusing to organize and compact carbon nanofibers in a mineral oil mixture. The result is a decrease in the composite electrical resistivity without an increase in the global volume fraction of the fibers in the composite and associated material cost. The composite consisted of Pyrograf PR-19-LHT carbon nanofibers mixed in light mineral oil at 1.6% volume fraction carbon nanofibers. The mixture was contained in a 1 cm × 1 cm × 4 cm glass cuvette. A PZT-4 piezoelectric transducer, epoxied to the external face of one of the sidewalls, generated the acoustic radiation forces in the container. A 1.179 MHz sinusoidal signal powered the transducer, producing a standing wave with 27 nodes and 13 antinodes in the container. A digital multimeter performed the 2-wire resistance measurement before, during and after focusing. Settling of the filler due to gravity resulted in an initial drop in the electrical resistance. Once the mixture reached steady state, toggling the signal power off and on also toggled the approximate electrical resistance between the 19.2 MOhms and 11.5 MOhms respectively. This work also presents a simple volume fraction model, which predicted that the focused resistance would be 34% of the unfocused value. In the experiment, acoustic focusing reduced the electrical resistance to 60% of the resistance in the unfocused mixture, demonstrating acoustic focusing as a method for reducing electrical conductivity within a composite.

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