Starting from an effective Fuchs-Sondheimer conduction model, the theoretical expression for the thermoelectric power of polycrystalline metal films is derived. From the approximate expression for thick films, a procedure is proposed to determine the variation in the electronic mean free path.

https://iopscience.iop.org/article/10.1088/0305-4608/10/9/016/pdf

Thermoelectric power of thin polycrystalline metal films in an effective mean free path model

The electrical resistivity, temperature coefficient of resistance (TCR) and thermoelectric power are measured on systematically annealed copper films formed by the vacuum evaporation method. From the measured quantities the scattering coefficient and the bulk mean free path of the conduction electrons are calculated. The electron mean free path is found to be 410+or-100 AA. The energy dependence of mean free path U and the energy dependence of Fermi surface area V are calculated from the thermoelectric power measurements as a function of thickness. Both U and V are found to be negative and thickness-dependent.

https://iopscience.iop.org/article/10.1088/0022-3727/9/1/015/pdf

Electrical resistivity, TCR and thermoelectric power of annealed thin copper films

The thermoelectric power and temperature coefficient of resistance of gold films has been measured and related to the energy dependence of both the mean free path of conduction electrons and the area of the Fermi surface. Values obtained for the quantities (dlnλ/dlnW)W=WF and (dlnA/dlnW)W=WF are − 0.60±0.04 and − 0.85±0.04, respectively. These quantities can be determined without knowing the surface‐scattering coefficient or sample thickness if the films have the same structure as the bulk material.

Thermoelectric Power of Thin Gold Films

Measurements of thermoelectric power, resistivity, and the temperature coefficient of resistance have been made on annealed silver films. The values obtained for the energy dependence of the mean free path of conduction electrons, [(∂ lnλ/∂ lnW)]W=WF, and the Fermi surface area, [(∂ lnA/∂ lnW)]W=WF, were 1.29 and −2.45, respectively.

Thermoelectric power of thin copper films

The thermopower of individual, 30 nm in diameter, Ni nanowires is measured as a function of bath temperature in the range 4–300 K. Boundary scattering of phonons at low temperatures ( 50 K) the absolute values of the thermopower are found to be smaller than the bulk values. This finding can be explained semi-quantitatively by considering electron scattering at grain boundaries. Any interpretation of size dependent thermopower in nanoscale ferromagnetic materials needs to explicitly consider the above effects.

S. F. Lin

Papers

Thermoelectric Power of Thin Metal Films