What Does Low Resistivity Mean?
A low resistivity indicates a material that readily allows the movement of electric charge. It is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. Resistivity is commonly represented by the Greek letter (rho). The SI unit of electrical resistivity is the ohm·meter (·m). Electrical conductivity or specific conductance is the reciprocal of electrical resistivity, and measures a material's ability to conduct an electric current.
Resistivity provides a reasonable approximation of the corrosivity of the environment — in general, the lower the resistivity, the more corrosive the environment is.
Corrosionpedia Explains Low Resistivity
Low resistivity is a material intrinsic property which readily allows the movement of electrons. Conversely, a high-resistivity material has a high electrical resistance and impedes the flow of electrons. Elements such as copper and aluminum are known for their low levels of resistivity. Silver and gold in particular have a very low resistivity, but for obvious cost reasons their use is restricted. Resistivity is affected by temperature — for most materials the resistivity increases with temperature. An exception is semiconductors (like silicon) in which the resistivity decreases with temperature.
Low resistivity and corrosivity are inversely related. The resistivity of the soil is one of many factors that influence the service life of a buried structure. High-resistivity soils are generally not as corrosive as low-resistivity soils. Soil resistivity may affect the material selection and the location of a structure.
The extremely low resistivity (high conductivity) of silver is characteristic of metals. An insulator like glass has low conductivity and a high resistivity. The conductivity of a semiconductor is generally intermediate, but varies widely under different conditions, such as exposure of the material to electric fields or specific frequencies of light, and, most important, with temperature and composition of the semiconductor material.