scholarly journals XI. Bakerian lecture.―The effect of temperature and pressure on the thermal conductivities of solids.—Part II. The effects of low temperatures on the thermal and electrical conductivities of certain approximately pure metals and alloys

1908 ◽  
Vol 208 (427-440) ◽  
pp. 381-443 ◽  
Keyword(s):  
Low Temperatures ◽  
Metals And Alloys ◽  
Effect Of Temperature ◽  
The Third ◽  
Electrical Conductivities ◽  
Pure Metals ◽  
Temperature And Pressure ◽  
Thermal Part ◽  
Thermal Conductivities

During the last fifty years a considerable amount of attention has been bestowed on the question of the variations of the thermal and electrical conductivities of metals with the temperature, hut the results obtained by different observers, especially of thermal conductivities, differed so widely from each other that the answer to the thermal part of the question long remained doubtful. In recent years, however, there has been an accumulation of evidence in favour of a slight decrease of thermal con­ductivity with increase of temperature from 0°C. to 100°C. in the case of most of the metals. The experiments of Lorenz, and more especially the careful work of Jager and Diesselhorst have contributed greatly to this result. In both these cases the experiments were limited to the range of temperature between 0°C. and 100°C., and it seemed advisable, in view of the importance of both questions in the electronic theories of conduction of heat and electricity in metals, to extend the range over which the theories could be tested, particularly in the direction of low temperatures, where the experiments of Dewar and Fleming had already furnished information as to the electrical conductivities. The present paper contains an account of the measurements of the thermal and electrical conductivities carried out for this purpose, and the results obtained. The first section deals with measurements of the thermal, the second with measurements of the electrical, conductivities of certain metals and alloys, and the third section compares the results with the electronic theories.

scholarly journals The thermal conductivities of certain approximately pure metals and alloys at high temperatures

1931 ◽  
Vol 134 (823) ◽  
pp. 57-76 ◽  
Keyword(s):  
Heat Flow ◽  
High Temperatures ◽  
Heat Losses ◽  
Metals And Alloys ◽  
Maximum Temperature ◽  
Internal Heating ◽  
Heating Coil ◽  
Pure Metals ◽  
Guard Tube ◽  
Thermal Conductivities

Measurements have been made by several observers on the thermal conductivities of metals and alloys up to high temperatures. Heat losses to the surroundings become large at high temperatures, hence the guard tube method, which to a great extent eliminates these losses, has been popular for work at these temperatures. This method was described and used by Berget in 1888, and later by Wilkes. These observers measured the rate of heat flow by a calorimetric method, which is not suitable for work at high temperatures. Honda and Simidu, using an internal heating coil, determined the heat flow from the energy input and were able to obtain results for nickel and steel to over 800°C. More recently, Schofield, using the guard tube method with an internal heating coil, has obtained results up to a maximum temperature of 700°C. with five metals. The present work was undertaken with a view to continuing the work of Professor C. H. Lees on the effect of temperatures between —160°C. and 15°C. on the thermal conductivities of nine metals and six alloys.

LORENZ NUMBERS OF PURE ALUMINUM, SILVER, AND GOLD AT LOW TEMPERATURES

1963 ◽  
Vol 41 (12) ◽  
pp. 2026-2033 ◽  
Author(s):  
E. W. Fenton ◽  
J. S. Rogers ◽  
S. B. Woods
Keyword(s):  
Low Temperatures ◽  
Experimental Error ◽  
Pure Aluminum ◽  
Electron Interaction ◽  
Lorenz Number ◽  
Electrical Conductivities ◽  
Lattice Waves ◽  
Pure Metals

Measurements have been made of the thermal and electrical conductivities at low temperatures on specimens of pure aluminum, silver, and gold. The resistivities caused by scattering of the electrons by lattice waves and by impurities have been separated and the Lorenz number has been deduced for these specimens. The Lorenz number calculated from the impurity resistivities for these pure metals agrees with the theoretical Sommerfeld value within an experimental error of about [Formula: see text]. The possible influence of an electron–electron interaction on these results is discussed.

scholarly journals The effects of temperature and pressure on the thermal conductivities of solids. Part II.—The effect of low temperatures on the thermal conductivities of pure metals and alloys

1908 ◽  
Vol 80 (536) ◽  
pp. 143-145 ◽  
Keyword(s):  
Olive Oil ◽  
Thermal Contact ◽  
Metals And Alloys ◽  
Copper Tube ◽  
External Diameter ◽  
Electrical Conductivities ◽  
Effects Of Temperature ◽  
The Difference ◽  
A Current ◽  
Thermal Conductivities

The object of the work described in the present paper was to extend the measurements of Thermal Conductivities of Metals and Alloys made by Lorenz, Jäger and Diesselhorst, and others at temperatures between 0°C. and 100°C. down to the temperature of liquid air, and thus provide a means of comparing the Thermal and Electrical Conductivities of these substances over a much wider range of temperature than has hitherto been possible. The method adopted was a modification of that used originally by Wiedemann and Franz. A rod of the metal, 7 or 8 cm. long, 0∙6 cm. in diameter, was placed in the axis of a vertical copper tube of 2∙7 cm. internal 3∙3 cm. external diameter, 9∙5 cm. long, closed at the top. The lower end of the rod fitted into a copper disc, which in its turn fitted into the lower end of the copper tube. The joints were accurately made and were smeared with olive oil to exclude air and improve the thermal contact. The heat which flowed along the rod was supplied electrically by means of a current through a fine platinoid wire wound on a short thin brass sleeve, which was slipped on to the upper end of the rod. The difference of temperatures at two points of the rod, between the heating coil and the point where the rod entered the disc forming the lower end of the tube, was measured by means of two platinum thermometers, the wires of which were wound on two short thin brass sleeves, capable of sliding along the rod. The three sleeves fitted the rod closely, and thermal contact was improved by smearing rod and sleeves with a little olive oil.

scholarly journals The flow in metals under large constant stresses

1914 ◽  
Vol 90 (619) ◽  
pp. 329-342 ◽  
Keyword(s):  
High Temperature ◽  
Viscous Flow ◽  
Low Temperatures ◽  
Effect Of Temperature ◽  
Initial Part ◽  
Time Curve ◽  
Permanent Set ◽  
Pure Metals ◽  
Metallic Wires

§1. The object of this research was to examine the general laws of flow in metallic wires when extended in the region of large permanent set by stresses kept constant throughout the flow. Previously I have investigated in detail the flow for one metal, lead, and put forward some empirical laws; it was desired to see if these laws could be extended to other metals, and especially to investigate the effect of temperature on the nature of the flow. For lead, rise of temperature causes a very rapid increase in the rate of the viscous part of the flow ( loc. cit. ); hence it seemed likely that at very low temperatures the viscous part of the flow would case altogether, although large permanent extensions might be obtainable, and thus lead might behave in this respect as iron behaves at atmospheric temperatures. Similarly iron at a high temperature might behave like lead at atmospheric temperatures. It was also desired to see if very pure metals behaved in the same way as commercial metals, for it has been supposed that the nonviscous character of the initial part of the extension-time curve is due to impurities. Further, the properties of the viscous flow itself were to be investigated in greater detail. Investigation on these points are described in this paper; a summary of the results will be found in §10. Incidentally, in the case of alloys, a type of flow not hitherto observed has been found.

scholarly journals Effects of temperature and pressure on the thermal conductivities of solids. Part I. The effect of temperature on the thermal conductivities of some electrical insulators

1905 ◽  
Vol 204 (372-386) ◽  
pp. 433-466 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Experimental Work ◽  
Effect Of Temperature ◽  
Opposite Conclusion ◽  
Effects Of Temperature ◽  
Temperature And Pressure ◽  
Thermal Conductivities

The question as to whether the thermal conductivity of a solid varies with temperature is an important one, and a considerable amount of attention has been bestowed on it. The experimental work which has been done cannot, however, be said to have led to a definite conclusion, owing to the discrepancies between the results obtained by different observers. Although the more recent of these results have produced a general disbelief of the idea which prevailed a few years ago, that the thermal conductivity of a solid would increase as the temperature increased, yet they do not justify the opposite conclusion being drawn.

Thermal Conductivities of Pure Metals at Low Temperatures: Mercury

1957 ◽  
Vol 106 (5) ◽  
pp. 927-933 ◽  
Author(s):  
R. T. Webber ◽  
D. A. Spohr
Keyword(s):  
Low Temperatures ◽  
Pure Metals ◽  
Thermal Conductivities

scholarly journals The effects of temperature and pressure on the thermal conductivities of bodies. Part I.–The effect of temperature on the thermal conductivities of some electrical insulators.

1905 ◽  
Vol 74 (497-506) ◽  
pp. 337-338 ◽  
Author(s):  
Charles Herbert Lees ◽  
Arthur Schuster
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistance ◽  
Electrical Current ◽  
Effect Of Temperature ◽  
Thin Cylinder ◽  
Heating Wire ◽  
Effects Of Temperature ◽  
Temperature And Pressure ◽  
At Will ◽  
Thermal Conductivities

The substance whose thermal conductivity is to be determined has the form of a cylinder about 8 cms. long, 2 cms. diameter, and is surrounded by a thin cylinder of brass, which on account of its comparatively high thermal conductivity, makes the outer surfaces of the substance isothermal surfaces. The brass cylinder is placed in a Dewar The heat is supplied by the passage of an electrical current through platinoid wire embedded in the substance parallel to the axis of the cylinder, and about .4 cm. distant from it. The amount of heat generated is determined by the current through the wire and the potential difference between its ends. The temperature is measured by the electrical resistance of two short spirals of No. 40 pure platinum wire, down the centre of one of which the heating wire passes. To eliminate errors due to want of symmetry, a second heating wire passes down the centre of the second spiral, and the heating current may be sent through either or both at will.

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