Thermal Diffusivity of Semiconductors Evaluated by Differential PPE Method

Thermal diffusivity of the sintered semiconductors was measured by the photopyroelectric (PPE) method. The measurement based on the phase-modulation frequency characteristics was shown to give superior results, eliminating errors expected in the conventional signal amplitude-distance characteristics measurements. Thermal diffusivities of the melt-grown and hot-pressed samples were found to be αmelt(c⊥) = 0.014 cm2/s, αmelt(c//) = 0.011 cm2/s, αhot(c⊥) = 0.012 cm2/s, and αhot(c//) = 0.008 cm2/s, depending on the relation between the c-axis direction of grain and thermal flow direction. The thermal diffusivity of the hot-pressed samples shows a strong dependence on the hot-press pressure through the orientation factor.

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Photopyroelectric Measurement of the Thermal Diffusivity of Recrystallized High Purity Aluminum

Research in Nondestructive Evaluation ◽

10.1080/09349849108968041 ◽

1991 ◽

Vol 3 (1) ◽

pp. 69-80

Author(s):

S. B. Peralta ◽

S. C. Ellis ◽

C. Christofides ◽

A. Mandeiis ◽

H. Sang ◽

...

Keyword(s):

Thermal Diffusivity ◽

High Purity ◽

High Purity Aluminum

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Light scattering and calorimetric study of the thermal diffusivity of glycerol, liquid and glass

Journal de Physique ◽

10.1051/jphys:01979004007069300 ◽

1979 ◽

Vol 40 (7) ◽

pp. 693-700 ◽

Cited By ~ 14

Author(s):

C. Allain ◽

P. Lallemand

Keyword(s):

Thermal Diffusivity ◽

Light Scattering ◽

Calorimetric Study

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THERMAL DIFFUSIVITY OF POLYMER FOILS - SEMICRYSTALLINE PETP AND PE - AS A FUNCTION OF DRAWING

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1983674 ◽

1983 ◽

Vol 44 (C6) ◽

pp. C6-463-C6-467 ◽

Cited By ~ 6

Author(s):

B. Merté ◽

P. Korpiun ◽

E. Lüscher ◽

R. Tilgner

Keyword(s):

Thermal Diffusivity ◽

Polymer Foils

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About definition of the local entropy rate of production in experiment of pulse electric heating

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2020-3-29-34 ◽

2020 ◽

pp. 29-34

Author(s):

Alexandr V. Kostanovskiy ◽

Margarita E. Kostanovskaya

Keyword(s):

Thermal Diffusivity ◽

Electric Heating ◽

Thermal Capacity ◽

Entropy Rate ◽

Initial Time ◽

Local Entropy ◽

Linear Mode ◽

Electric Capacity ◽

Definition Of ◽

Pulse Electric

Work is devoted to studying of a linear mode thermodynamic – a mode which is actively investigated now. One of the main concepts of a linear mode – local entropy rate of production. The purpose of given article consists in expansion of a circle of problems for which it is possible to calculate a local entropy rate of production, namely its definition, using the experimental “time-temperature” curves of heating/cooling. “Time-temperature” curves heating or cooling are widely used in non-stationary thermophysical experiments at studying properties of substances and materials: phase transitions of the first and second sort, a thermal capacity, thermal diffusivity. The quantitative substantiation of the formula for calculation of the local entropy rate of production in which it is used thermogram (change of temperature from time) which is received by a method of pulse electric heating is resulted. Initial time dependences of electric capacity and temperature are measured on the sample of niobium in a microsecond range simultaneously. Conformity of two dependences of the local entropy rate of production from time is shown: one is calculated under the known formula in which the brought electric capacity is used; another is calculated, using the thermogram.

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