LOW-TEMPERATURE THERMOELECTRIC POWER OF HEAVILY DOPED n-TYPE GERMANIUM

1965 ◽  
Vol 43 (11) ◽  
pp. 2008-2020 ◽  
Author(s):  
F. T. Hedgcock ◽  
D. P. Mathur
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Thermoelectric Power ◽  
Temperature Region ◽  
Magnetic Scattering ◽  
Zero Magnetic Field ◽  
Large Temperature ◽  
Susceptibility Data ◽  
Antiferromagnetic Ordering ◽  
Heavily Doped

A large, temperature-dependent component in the low-temperature thermoelectric power of heavily doped n-type germanium has been observed in the temperature region of liquid helium. All of the samples (6.8–62 × 1017 per cm3) exhibit a negative magnetoresistance in the low-temperature region which saturates at reasonably low magnetic-field values. On the basis of an assumed magnetic scattering, the magnetoresistance and magnetic susceptibility data have been analyzed in order to estimate the magnitude and concentration of the localized magnetic moment of the spin-scattering center, and also to estimate the exchange integral giving rise to the coupling between the mobile carriers and the localized impurity electrons. The resistivity behavior, in both a finite and zero magnetic field, appears to be best described by assuming an antiferromagnetic transition in the region of the thermoelectric anomaly. Attempts are made to interpret the observed temperature dependence of the thermopower. However, as yet, there is no quantitative theory to predict the thermoelectric behavior of a degenerate semiconductor in the presence of antiferromagnetic ordering.

Magnetic Prehistory in the Heat Capacity of the Low-Temperature Superconductors

2015 ◽  
Vol 233-234 ◽  
pp. 741-744
Author(s):  
Sergey Mikhailovich Podgornykh
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Ring Specimen ◽  
Trapped Flux ◽  
The Magnetic Field

Effect of the magnetic prehistory on the temperature dependence of the heat capacity of the superconducting Pb, La, Sn. has been studied. As soon as the external magnetic field riches the valueHext=HCthe superconductivity is completely destroyed. The trapped flux was produced in the ring specimen after the magnetic field was turned off atT<TC. We observed a difference of the value of the heat capacity between zero field cooled (ZFC) and field cooled (FC) states in zero magnetic field for the ring specimen. It is found that the FC heat capacity is smaller than the heat capacity both in the normal and in superconducting states.

scholarly journals Теплоемкость скандобората NdSc-=SUB=-3-=/SUB=-(BO_3)-=SUB=-4-=/SUB=-

2021 ◽  
Vol 63 (12) ◽  
pp. 2226
Author(s):  
Е.В. Еремин ◽  
Н.Д. Андрюшин ◽  
И.А. Гудим ◽  
М.С. Павловский ◽  
В.Р. Титова
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Low Temperature ◽  
Single Crystals ◽  
Temperature Region ◽  
Applied Magnetic Field ◽  
Molar Heat Capacity ◽  
Group Method ◽  
Lattice Contribution ◽  
Einstein Model

Single crystals of trigonal neodymium scandoborate NdSc3(BO3)4 were grown by the group method from a solution-melt based on bismuth trimolybdate. The molar heat capacity C(T) was studied in the temperature range 2-300 K and magnetic fields up to 9 T. The experimental curve was approximated by the combined Debye-Einstein model. The lattice contribution was determined from ab-initio calculations. Schottky anomaly was observed in the low-temperature region C(T) with the applied magnetic field.

Magnetism and Structural Behavior of CeRuSn Single Crystal

2012 ◽  
Vol 194 ◽  
pp. 40-44 ◽  
Author(s):  
Jan Fikáček ◽  
Jiří Prchal ◽  
Jan Prokleška ◽  
Ivana Císařová ◽  
Vladimír Sechovský
Keyword(s):  
Magnetic Field ◽  
Electrical Resistivity ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Specific Heat ◽  
Single Crystals ◽  
Structural Behavior ◽  
Large Temperature ◽  
Temperature Hysteresis ◽  
Antiferromagnetic Transition

We have synthesized CeRuSn single crystals and performed measurements of electrical resistivity and specific heat. At high temperatures, abrupt transitions were observed at 290 and 225 K in electrical resistivity during cooling. Both transitions are connected with a large temperature hysteresis. Low temperature properties are dominated by an antiferromagnetic transition at 2.9 K, which involves only half of cerium ions, leaving the rest of them non-magnetic. A significant magnetocrystalline anizotropy was revealed by application of external magnetic field.

scholarly journals Low-Temperature Properties of Compensated Ge Films Used for Cryogenic Thermometers

2002 ◽  
Vol 719 ◽  
Author(s):  
V. F. Mitin ◽  
V. V. Kholevchuk ◽  
V. K. Dugaev ◽  
M. Vieira
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Low Temperature ◽  
Theoretical Study ◽  
Temperature Sensors ◽  
Temperature Resistance ◽  
Gaas Substrates ◽  
Heavily Doped ◽  
Low Temperature Resistance ◽  
Good Agreement

AbstractLow temperature microsensors are designed for cryogenic applications. As a material for the sensors we use heavily doped compensated Ge films deposited on the semi-insulating GaAs substrates. We present the results of experimental and theoretical study of the low temperature resistance as a function of temperature and magnetic field for some models of temperature sensors. The computer simulations show a good agreement with experimental data.

Low-Temperature Thermomagnetic Effects in Graphite

1972 ◽  
Vol 50 (20) ◽  
pp. 2444-2450 ◽  
Author(s):  
J. P. Jay-Gerin
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Thermoelectric Power ◽  
Satisfactory Agreement ◽  
Quantum Mechanical ◽  
Phonon Drag ◽  
Phonon Coupling

The low-temperature thermoelectric power (TEP) and the Nernst–Ettingshausen (NE) coefficient of graphite due to phonon drag are studied in the presence of a magnetic field H directed along the c axis and small enough for the quantum-mechanical character of the motion of the carriers to be negligible. Expressions for the TEP and the NE coefficient are obtained on the basis of the theory of Jay-Gerin and Maynard, in which the phonon-drag TEP of graphite in the absence of a magnetic field is linked with the Kohn screening anomaly. The results suggest a method by which information might be obtained about the strength of the electron– and hole–phonon coupling directly from experiment. A satisfactory agreement is found with the measurements of Takezawa, Tsuzuku, Ono, and Hishiyama and of Tamarin, Shalyt, and Volga.

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