The specific heat of pure copper and of some dilute copper + iron alloys showing a minimum in the electrical resistance at low temperatures

1961 ◽  
Vol 263 (1315) ◽  
pp. 494-507 ◽  
Keyword(s):  
Specific Heat ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Pure Copper ◽  
Iron Alloys ◽  
Absolute Zero ◽  
Iron Ions ◽  
Temperature Range ◽  
Dilute Alloys ◽  
Resistance Minimum

The specific heat of pure copper and of some dilute alloys of iron in copper, containing approximately 0.05, 0.1 and 0.2at. % iron, have been measured in the temperature range 0.4 to 30 °K. The electrical resistance of the copper + iron alloys has been measured from 0.4 to 80 °K. The alloys show specific-heat anomalies which probably extend from the absolute zero of temperature to the region of the minimum in electrical resistance. The entropy contents of the anomalies lie close to the value R In 2 per mole of iron suggesting that only two energy states of the iron ions are involved in the resistance minimum phenomena. The results are discussed in relation to existing theories.

An anomaly in the specific heat below 3 °K of copper containing hydrogen

1969 ◽  
Vol 47 (14) ◽  
pp. 1485-1491 ◽  
Author(s):  
Neil Waterhouse
Keyword(s):  
Specific Heat ◽  
Molecular Hydrogen ◽  
Pure Copper ◽  
Solid Hydrogen ◽  
Rotational State ◽  
Experimental Results ◽  
Ortho Hydrogen ◽  
Temperature Range ◽  
A Value ◽  
Heat Curve

The specific heat of copper heated in hydrogen at 1040 °C has been measured over the temperature range 0.4 to 3.0 °K and found to be anomalous. The anomaly occurs in the same temperature range as the solid hydrogen λ anomaly which, in conjunction with evidence of ortho to para conversion of hydrogen in the sample, suggests the presence of molecular hydrogen in the copper. The anomaly reported by Martin for "as-received" American Smelting and Refining Company (ASARCO) 99.999+ % pure copper has been briefly compared with the present results. The form of the anomaly produced by the copper-hydrogen specimen has been compared with Schottky curves using the simplest possible model, that for two level splitting of the degenerate J = 1 rotational state of the ortho-hydrogen molecule.Maintenance of the copper-hydrogen sample at ~20 °K for approximately 1 week removed the "hump" in the specific heat curve. An equation of the form Cp = γT + (464.34/(θ0c)3)T3 was found to fit these experimental results and produced a value for γ which had increased over that for vacuumannealed pure copper by ~2%.

THE EFFECT OF PRESSURE ON THE ELECTRICAL RESISTANCE OF LITHIUM

1963 ◽  
Vol 41 (8) ◽  
pp. 1381-1384 ◽  
Author(s):  
D. Gugan
Keyword(s):  
Hydrostatic Pressure ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Pressure Coefficient ◽  
Residual Resistivity ◽  
Effect Of Pressure ◽  
Dilute Alloys

The change of resistance of lithium with hydrostatic pressure has been studied at low temperatures. Anomalous results have been found at all temperatures. The pressure coefficient of residual resistivity of dilute alloys of magnesium in lithium has been found to depend on the structure of the parent lattice.

scholarly journals Effect of hydrogen on the electrical resistance of NbSe2 in a wide temperature range

2021 ◽  
Author(s):  
A. Chroneos ◽  
G. Ya. Khadzhai ◽  
V. I. Biletskyi ◽  
M. V. Kislitsa ◽  
R. V. Vovk
Keyword(s):  
Solid Solution ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Charge Density Wave ◽  
Density Wave ◽  
Temperature Range ◽  
Niobium Diselenide ◽  
Dissolved Hydrogen ◽  
A Charge ◽  
Increasing Temperature

AbstractThe electrical resistivity of niobium diselenide (NbSe2) with hydrogen was investigated in the temperature range Tc – 300 K. It was determined that hydrogen inhibits the formation of a charge density wave. It was shown that hydride phase with niobium is formed due to hydrogen in NbSe2 layers at low temperatures, which decomposes with increasing temperature to form a solid solution. The temperature dependence of the resistivity is approximated by the Bloch–Grüneisen function. The approximation parameters vary depending on the amount of dissolved hydrogen.

scholarly journals Magnetoresistance of Bi2Se3 Whiskers at Low Temperatures

2017 ◽  
Vol 18 (2) ◽  
pp. 194-197
Author(s):  
N.S. Liakh-Kaguy ◽  
A.A. Druzhinin ◽  
I.P. Ostrovskii ◽  
Yu.N. Khoverko
Keyword(s):  
Magnetic Field ◽  
Superconducting State ◽  
Low Temperatures ◽  
Kondo Effect ◽  
Doping Concentration ◽  
Electron Localization ◽  
Sharp Drop ◽  
Temperature Range ◽  
Pd Doping ◽  
Resistance Minimum

Temperature dependencies of Bi2Se3 whiskers’ resistance with Pd doping concentration of 1´1019 cm-3 where measured in temperature range 4.2 - 300 K. At temperature 5.3 K a sharp drop in the whisker resistance was found. The observed effect is likely connected with contribution of two processes such as the electron localization in the whiskers and transition in superconducting state at temperature 5.3 K, which is likely result from Pd complexes.Transversemagnetoresistance in n-type Bi2Se3 whiskers with Pd doping concentration in the vicinity to themetal-insulator transition (MIT) from metal side of the transition were studied in magnetic field 0 -10 T. For the whiskers a resistance minimum was observed at temperature about 25 K that is connected with Kondo effect.

scholarly journals Specific Heat of Holmium in Gold and Silver at Low Temperatures

2020 ◽  
Author(s):  
Matthew Herbst ◽  
Andreas Reifenberger ◽  
Clemens Velte ◽  
Holger Dorrer ◽  
Christoph E. Düllmann ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Low Temperature ◽  
Specific Heat ◽  
Low Temperatures ◽  
Hyperfine Splitting ◽  
Total Angular Momentum ◽  
Dilute Alloys ◽  
Dipole Interactions ◽  
Temperature Ranges ◽  
Additional Concentration

Abstract The specific heat of dilute alloys of holmium in gold and in silver plays a major role in the optimization of low temperature microcalorimeters with enclosed $$^{163}{{\text {Ho}}}$$ 163 Ho , such as the ones developed for the neutrino mass experiment ECHo. We investigate alloys with atomic concentrations of $$x_{{{\text {Ho}}}}=0.01{-}4\%$$ x Ho = 0.01 - 4 % at temperatures between 10 and $$800\,{{{\hbox {mK}}}}$$ 800 mK . Due to the large total angular momentum $$J=8$$ J = 8 and nuclear spin $$I=7/2$$ I = 7 / 2 of $${{\text {Ho}}}^{3+}$$ Ho 3 + ions, the specific heat of Au:Ho and Ag:Ho depends on the detailed interplay of various interactions, including contributions from the localized 4f electrons and nuclear contributions via hyperfine splitting. This makes it difficult to accurately determine the specific heat of these materials numerically. Instead, we measure their specific heat by using three experimental setups optimized for different concentration and temperature ranges. The results from measurements on six holmium alloys demonstrate that the specific heat of these materials is dominated by a large Schottky anomaly with its maximum at $$T\approx 250\,{{{\hbox {mK}}}}$$ T ≈ 250 mK , which we attribute to hyperfine splitting and crystal field interactions. RKKY and dipole–dipole interactions between the holmium atoms cause additional, concentration-dependent effects. With regard to ECHo, we conclude that for typical operating temperatures of $$T\le 20\,{{{\hbox {mK}}}}$$ T ≤ 20 mK , silver holmium alloys with $$x_{{{\text {Ho}}}}\gtrsim 1\%$$ x Ho ≳ 1 % are suited best.

The electrical resistance of some dilute alloys of the noble metals and Re at low temperatures

Physica ◽  
1964 ◽  
Vol 30 (6) ◽  
pp. 1124-1130 ◽  
Author(s):  
B. Knook ◽  
W.M. Star ◽  
H.J.M. Van Rongen ◽  
G.J. Van den Berg
Keyword(s):  
Electrical Resistance ◽  
Low Temperatures ◽  
Noble Metals ◽  
Dilute Alloys

THE SPECIFIC HEAT OF COPPER FROM 20° TO 300 deg;K

1960 ◽  
Vol 38 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Douglas L. Martin
Keyword(s):  
Specific Heat ◽  
Pure Copper ◽  
Annealed Sample ◽  
Rolled Material ◽  
Temperature Range ◽  
Specific Heats ◽  
Commercially Pure ◽  
Cold Rolled ◽  
Cold Worked ◽  
Annealed Copper

The specific heats of commercially pure cold-rolled copper and of annealed and heavily cold-worked 99.999% pure copper have been measured in the temperature range 20° to 300 deg;K. When results are averaged over the whole temperature range of measurement the specific heat of the pure cold-worked copper is about 0.15% above that of the pure annealed sample while results for the commercially pure cold-rolled material lie in an intermediate position. Results on a given sample are reproducible within 0.05%. The entropy of pure annealed copper at 298.15 deg;K is 7.92 ± 0.04 cal/°K g-atom.

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