Superconductivity, as defined by Merriam-Webster, is a complete disappearance of electrical resistance in a substance especially at very low temperatures. That is a very basic definition that is not completely accurate (which will be explained later). But, then what is a superconductor? In order to create a better, more detailed definition, the characteristics of superconducting materials should be understood. Superconductors are characterized by a repulsion of magnetic fields, which was discovered by W. Meissner and R. Ochsenfeld in 1933. This discovery occurred 22 years after the initial discovery of superconductors in 1911 by H. K. Onnes, when he observed a second characteristic of superconductors, a complete lack of electrical resistance. For a more detailed history of superconductors and their discoverers, click here.
As you've probably seen, the first definition did not make mention of the repulsion of magnetic fields, called the Meissner effect, but that's not why that definition is flawed, as this is a result of the lack of resistance. Rather it is the second part, the very low temperature part, which is wrong. As scientists are able to synthesize superconductors, higher temperature ones have been created. High being relative, since the temperature are still cold, but they are much higher than the 4 K Mercury that Onnes discovered superconductivity with.
So, superconductors, what are they? They are materials, usually metals, that when brought down below a certain temperature experiences a complete lack of resistance. This definition (and brief history lesson) should make understanding superconductivity a bit easier.
As you've probably seen, the first definition did not make mention of the repulsion of magnetic fields, called the Meissner effect, but that's not why that definition is flawed, as this is a result of the lack of resistance. Rather it is the second part, the very low temperature part, which is wrong. As scientists are able to synthesize superconductors, higher temperature ones have been created. High being relative, since the temperature are still cold, but they are much higher than the 4 K Mercury that Onnes discovered superconductivity with.
So, superconductors, what are they? They are materials, usually metals, that when brought down below a certain temperature experiences a complete lack of resistance. This definition (and brief history lesson) should make understanding superconductivity a bit easier.
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