The specific heat of metals and alloys at low temperatures

1957 ◽  
Vol 240 (1222) ◽  
pp. 321-332 ◽  
Keyword(s):  
Fermi Surface ◽  
Specific Heat ◽  
Liquid Helium ◽  
Brillouin Zone ◽  
Low Temperatures ◽  
Metals And Alloys ◽  
Thermal Excitation ◽  
Electronic Specific Heat ◽  
Conduction Electrons ◽  
Elastic Shear

The effect of thermal excitation of the conduction electrons on the elastic shear constants is investigated in a metal in which the Fermi surface lies close to the Brillouin-zone boundaries. It is shown that in these circumstances electron-lattice interaction leads to an addi­tional term in the specific heat, linear in the temperature in the liquid-helium range, which, therefore, augments the pure electronic specific heat. The variation in magnitude of this linear term is considered in the α-brasses. It is suggested that this is the physical effect underlying the peculiarities of the ‘electronic’ specific heat of these alloys.

ON THE FERMI SURFACE OF BETA BRASS

1966 ◽  
Vol 44 (8) ◽  
pp. 1787-1793 ◽  
Author(s):  
J. -P. Jan
Keyword(s):  
Fermi Surface ◽  
Specific Heat ◽  
Brillouin Zone ◽  
Present Model ◽  
Energy Gap ◽  
Electronic Specific Heat ◽  
Cone Model ◽  
Best Fit ◽  
Structure Calculations ◽  
Good Agreement

Results of de Haas – van Alphen effect measurements on ordered β′-CuZn (50 at.% Zn) provide the area of contact of the Fermi surface with the faces of the second (dodecahedral) Brillouin zone. If the energy gaps at the faces of the first (cubic) Brillouin zone are ignored, a 12-cone model can be worked out. An energy gap of 3.49 eV at the second-zone faces and an effective mass m* = 1.045me, provide the best fit between the 12-cone model, the area of contact, and the measured electronic specific heat. The gap is in good agreement with present band-structure calculations. The first-zone gaps do give rise to de Haas – van Alphen oscillations, but their neglect in the present model should not affect the calculated electronic specific heat appreciably.

Low-temperature Properties of U2Co2InH1.9

2007 ◽  
Vol 62 (7) ◽  
pp. 977-981 ◽  
Author(s):  
Ladislav Havela ◽  
Khrystyna Miliyanchuk ◽  
Laura C. J. Pereira ◽  
Eva Šantavá
Keyword(s):  
High Pressure ◽  
Magnetic Susceptibility ◽  
Specific Heat ◽  
Low Temperatures ◽  
Magnetic Order ◽  
Parent Compound ◽  
Spin Fluctuations ◽  
High Magnetic Fields ◽  
Electronic Specific Heat ◽  
Metamagnetic Transition

Abstract U2Co2InH1.9, synthesized by high-pressure hydrogenation of U2Co2In, crystallizes in the tetragonal structure similar to the parent compound, expanded by 8.4 %. Although U2Co2In is a weak paramagnet, its hydride shows properties suggesting a proximity to the magnetic order. Its magnetic susceptibility exhibits a maximum at T = 2.4 K, ascribed to spin fluctuations. Magnetization at low temperatures goes through a metamagnetic transition between 2 - 3 T. The specific heat characteristics, with a pronounced upturn of Cp/T vs. T at low temperatures which can be fitted using an additional −T 1/2 term, resemble the behaviour of U2Co2Sn. The γ coefficient of the electronic specific heat, reaching 244 mJ mol−1 K−2, is gradually suppressed by high magnetic fields.

Nodal gap behavior of Bi2Sr2−xLnxCuO6+δ (Ln = La, Eu) investigated by specific heat measurements

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542014 ◽  
Author(s):  
M. Shimizu ◽  
Y. Moriya ◽  
S. Baar ◽  
N. Momono ◽  
Y. Amakai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Magnetic Fields ◽  
Fermi Surface ◽  
Specific Heat ◽  
Excitation Spectrum ◽  
Cuprate Superconductors ◽  
Electronic Excitation ◽  
Linear Term ◽  
Electronic Specific Heat ◽  
Low Temperature Specific Heat

We performed low-temperature specific heat measurements on slightly underdoped samples of monolayer cuprate superconductors [Formula: see text] (Ln = La, Eu, Ln-Bi2201) under magnetic fields [Formula: see text]. In La-Bi2201, the coefficient [Formula: see text] of [Formula: see text]-linear term in the electronic specific heat [Formula: see text] at [Formula: see text] shows [Formula: see text] dependence, as expected in [Formula: see text] -wave superconductors. In Eu-Bi2201, [Formula: see text] shows almost the same [Formula: see text] dependence as that of La-Bi2201 below [Formula: see text] T, while [Formula: see text] is suppressed above [Formula: see text] T and deviates downward from the [Formula: see text] curve of La-Bi2201. This result suggests the the gap and the electronic excitation spectrum near nodes are modified in Eu-Bi2201 except the region of the Fermi surface in the immediate vicinity of nodes.

Theoretical Study of the Indirect Quadrupole-Quadrupole Interactions in Metals and Alloys

1990 ◽  
Vol 45 (3-4) ◽  
pp. 380-384 ◽  
Author(s):  
N. G. Fazleyev
Keyword(s):  
Fermi Surface ◽  
Dielectric Function ◽  
Quadrupole Interaction ◽  
Function Method ◽  
Theoretical Study ◽  
Exchange Interactions ◽  
Metals And Alloys ◽  
Conduction Electrons ◽  
Quadrupole Interactions ◽  
Paramagnetic Ions

Abstract The indirect multipole interactions of nuclei and impurity paramagnetic ions in metals and alloys via conduction electrons are investigated by means of the dielectric function method. The Hamiltonian of the indirect quadrupole-quadrupole interaction of impurity paramagnetic ions and nuclei is constructed selfconsistently, taking into account the exchange interactions and correlations of the conduction electrons as well as the antishielding effects. It is shown that the energy of these indirect quadrupole interactions of the nuclei and the paramagnetic ions decreases with the distance as R ~ 3 , oscillating with a period which is determined by the wave vector on the Fermi surface and the distance R. The influence of these indirect quadrupole-quadrupole interactions on the width and shape of the NMR lines is studied.

The relaxation time of conduction electrons in the noble met

1963 ◽  
Vol 275 (1361) ◽  
pp. 209-217 ◽  
Keyword(s):  
Electrical Conductivity ◽  
Relaxation Time ◽  
Boltzmann Equation ◽  
Fermi Surface ◽  
Low Temperatures ◽  
Lattice Vibrations ◽  
Thermo Electric ◽  
Multiply Connected ◽  
Conduction Electrons ◽  
Experimental Values

The Boltzmann equation for scattering by impurities and lattice vibrations is solved numerically for a metal having a multiply-connected Fermi surface. It is found that the relaxation time for scattering by lattice vibrations at high temperatures or by impurities is approximately constant over the Fermi surface. For scattering by lattice vibrations at low temperatures the relaxation time is highly anisotropic. These results are consistent with the experimental values of the electrical conductivity but cannot predict a positive thermo ­ electric power.

Electronic Specific Heat of Vanadium Compounds at Low Temperatures

2021 ◽  
Author(s):  
Vad. I. Surikov ◽  
Val. I. Surikov ◽  
Yu. V. Kuznetsova ◽  
N. A. Semenyuk ◽  
O. V. Lyakh ◽  
...  
Keyword(s):  
Specific Heat ◽  
Low Temperatures ◽  
Electronic Specific Heat ◽  
Vanadium Compounds

Band Structure of Monovalent Metals and Their Alloys

1960 ◽  
Vol 13 (2) ◽  
pp. 238 ◽  
Author(s):  
PG Klemens
Keyword(s):  
Band Structure ◽  
Fermi Surface ◽  
Physical Properties ◽  
Specific Heat ◽  
Thermoelectric Power ◽  
Quantitative Comparison ◽  
Electronic Specific Heat ◽  
Phonon Drag ◽  
Conduction Properties

The consequences of the Bloch theory of the conduction properties of metals can be evaluated only for a band of spherical Fermi surface, isotropic in all respects. Quantitative comparison with observations is thus possible only for the monovalent metals. It appears that even the monovalent metals do not satisfy this requirement, but that their Fermi surface departs significantly from sphericity. The information derived from the various conduction properties and the electronic specific heat is discussed, paying attention to Umklapp processes and phonon drag effects. The thermoelectric power is difficult to interpret. Systematic measurements of the changes of various physical properties on alloying may provide useful information.

SPIN FLUCTUATIONS IN TCo2 STUDIED BY RESISTIVITY AND THERMOPOWER EXPERIMENTS (T = Y, Lu, Sc, Hf, Zr, Ce)

1993 ◽  
Vol 07 (01n03) ◽  
pp. 370-373 ◽  
Author(s):  
N. BARANOV ◽  
E. BAUER ◽  
E. GRATZ ◽  
R. HAUSER ◽  
A. MARKOSYAN ◽  
...  
Keyword(s):  
Low Temperature ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Temperature Region ◽  
Low Temperatures ◽  
Spin Fluctuations ◽  
General Tendency ◽  
Electronic Specific Heat ◽  
Temperature Dependent

The temperature dependence of the resistivity and the thermopower in the region from 4.2K up to 1000K for the six isostructural paramagnetic compounds TCo 2 (T=Y, Lu, Sc, Hf, Zr, Ce) is studied. The resistivity ρ (T) follows a T 2 dependence at low temperatures in all these compounds. Plotting the A values into an A vs. γ2 diagram shows that YCo 2, LuCo 2, and ScCo 2 are spinfluctuation systems (A and γ denote the coefficients in ρ (T) = ρ0 + AT 2 and that of the electronic specific heat, respectively) HfCo 2 and ZrCo 2 do not fit into this general tendency in the ( A , γ2)-diagram. The temperature dependent thermopower S(T) in YCo 2, LuCo 2 and ScCo 2 exhibits a pronounced minimum in the low temperature region. These minima are obviously connected with the existence of spin fluctuations (paramagnon-drag). Spin fluctuations in HfCo 2 and ZrCo 2 are less important. This we conclude also from the ten times smaller A-values and the missing minimum in the thermopower at low temperatures.

Heat capacity of electrons

2021 ◽  
pp. 345-352
Author(s):  
Geoffrey Brooker
Keyword(s):  
Heat Capacity ◽  
Fermi Surface ◽  
Density Of States ◽  
Low Temperatures ◽  
Conduction Electrons ◽  
More Care

“Heat capacity of electrons” is concerned with the heat capacity of conduction electrons in a metal. The heat capacity is usually of most interest at low temperatures. It is proportional to the density of states for electrons at the Fermi surface. The calculation showing this requires more care than is usually given.

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