What is the best conductor of electricity and why does increasing temperature increase the specific resistivity on conductors whereas decrease the specific resistance of semiconductors?
The resistivity of good metal conductors is defined by electron scattering on thermal excitations of the lattice. Same effect is present in semiconductors as well however there the increase of temperature also causes massive release of more carriers, usually an owelwhelming effect.
Well, one could argue that all superconductors are equally good conductors as they all have zero resistance, but I suspect superconductors aren’t what you meant. Among ordinary materials at room temperature silver has the lowest resistance. However conductivity alone is usually not the only factor when picking a conductor. Gold, platinum, copper, and aluminum are also good. Gold and platinum are very expensive but have the advantage of being noble metals that don’t corrode. They are also very malleable and can easily made into wires and contacts. However, they are mechanically weak so you have to consider breakage. These features make them particularly good for plating contacts. Small amounts, no mechanical strength required, and avoiding corrosion is critical. They are also excellent thermal conductors. Silver is still fairly expensive and also it corrodes, so it isn’t a popular choice for wires or contacts. On the other hand its chemical properties make it good for some electrical and thermal bonding applications. Copper is much cheaper and it is still a very good conductor of both electricity and heat. It oxidizes and corrodes, but high conductivity at low cost make it the standard for wiring. Ot can easily be coated with one of the others to avoid corrosion on contacts. Aluminum is a pretty good conductor and has the advantages of being stronger and corrosion resistant. Unlike noble metals it does oxidize, but the oxide forms a layer that stops and goes no further. The strength and corrosion resistance make aluminum a good choice for bare transmission lines. Also many general purpose wires that might be bent or worked often are made of aluminum so they can take the punishment. Aluminum is easier to machine than the soft metals, so it is also a good choice for complicated structures that need to be conductive.
It is interesting to note that room temperature good conductors do not turn to superconductivity easily. That is because supeconductivity needs good phonon (acoustic lattice exitation) coupling of electrons pairs via lattice.
Gentlemen,
Can we pause for a second and wonder why this question, in various guises, was asked a dozen times here on ResearchGate?
It truly makes one wonder if this is a legitimate question about a research topic, doesn't it? Perhaps Dr Naresh can shed light on the research that required such a shotgun-approach, when wikipedia explains conductivity well?
Dr Naresh,
I'll ask you directly: are you sincere in your interest in the origins of superconductivity or are you simply posting basic questions, hoping for people to answer, and so boost your RG 'score'?
You have posted literally hundreds of basic questions this year, most of which can be resolved with a Google search.
Why?
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