Superconductivity Superconductivity Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors, when cooled below a characteristic critical temperature. It was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8, 1911, in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor during its transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of
Tettje Clay-Jolles 1903 when she transferred to the University of Leiden. She was one of the few women who studied physics at the university. There she began her doctoral research on low-temperature physics under Heike Kamerlingh Onnes. She worked on her thesis until December 1908 when she left her studies to devote herself to her family. Clay-Jolles met and fell in love with Jacob Clay, another of Kamerlingh Onnes's students, and in 1908 the two were married. Later that year she left school to focus on her family. She spent the next twelve years raising the couple's three children. In 1920 the