[01] D. P. Nandedkar, Department of Electrical Engineering, Indian Institute of Technology, Bombay, Powai, Mumbai, India.

In the present paper an analysis of conductivity of noble metals near room temperature (~293⁰K where ⁰K is Degree Kelvin) is carried out. The extreme high conductivity of noble metals (specially Cu from cost point of view) make them suitable to find their use in connecting various circuit elements offering an extremely low resistance path of the connectors in the physics (Laboratory)/electric/electronic networks/circuits. Thus the importance of noble metals in physics (Laboratory)/electric/electronic engineering is obvious. Conductivity of noble metals near room temperature is analyzed and calculated here. The conductivity comes into picture due to limitation of current by collisions of conduction electrons with fixed ions undergoing coupled mass-vibrations at the temperature of the metal under consideration. The process of electron-ion collisions in the metal is described in terms of a collision frequency, using gas-kinetics. The collision frequency of an electron, with velocity corresponding to Fermi-energy, can be determined if effective collision cross-section of electron - ion collisions be known. In the present analysis, an expression for effective collision cross-section describing collisions of the electron with the ions undergoing thermal mass-vibrations is obtained. The effective collision cross-section is given by overall average of the resultant mean square value of amplitudes of the ion undergoing coupled mass-vibrations. Whence knowing the collision frequency, conductivity of the metal is obtained. Discrepancy of conductivities between theoretical and tabulated values from physical tables is attributed to anisotropic process of scattering of the electron at electron-ion collision. This analysis gives fairly well values of conductivities near room temperature for noble metals especially for gold, the ornamental metal. Purpose of this work is to illustrate in a simple manner how conductivity of the metal comes in picture by isotropic/anisotropic scattering of the electron at collisions with ions in the metal.

Noble-metals, Electron, Ions, Collisions, Coupled-Mass-Vibration, Ions, Conductivity, Room-Temperature

[01] Bardeen, J., (1940): “Electrical Conductivity of Metals”, Journal of Applied Physics, Vol. 11, pp. 88. [02] E. Justi, Leitfa ̈higkeit und Leitungsmechainsmus fester Stoffe, (1948): Vandenheek, Go ̈ttingen [03] V. Weisskopf, (1943): “On the theory of the electric resistance of metals”, Am. J. Phys., 11, 1. [04] E. Gru ̈neisen, (1933): Ann. Physik, 16, 530. [05] M. Blackman, (1951): Proc. Phys. Soc. (London), A64, 681. [06] P. G. Clemens, (1952): Proc. Phys. Soc. (Londn), A65, 71. [07] Max Born, (1963): “Atomic Physics” Seventh Edition (Reprinted), The English Language Book Society And Blackie & Son Ltd., London, Glasgow, Bombay (Mumbai). [08] Nandedkar D. P., (1983): “Some Electrical properties of plasma, noble metals and, intrinsic germanium and silicon (Parts I, II, and III) - Part II: Conductivity of Noble Metals” pp.1-3, Abstract-Record of the Silver Jubilee Symposium on “Electronics and Communications in the 80’s” held at I.I.T. Bombay, Powai, Mumbai, on Feb. 14-16. [09] Clark, J.B., (1970): New Physical and Mathematical Tables”, Revised (Reprinted) Edition, Oliver and Boyd Ltd., Edinburgh. [10] Lindsay, R.B., (1962): “physical Mechanics” Third (Reprinted) Edition, D. Van Nostrand Company, Inc., New York etc.