Pierre curie

Pierre was educated at home by his father, and in his early teens showed a strong aptitude for mathematics and geometry. By the age of 18 he had completed the equivalent of a higher degree, but did not proceed immediately to a doctorate due to lack of money. Instead he worked as a laboratory instructor.
In 1880, Pierre and his older brother Jacques demonstrated that an electric potential was generated when crystals were compressed. Shortly afterwards, in 1881, they demonstrated the reverse effect: that crystals could be made to deform when subject to an electric field. Almost all digital electronic circuits now rely on this phenomenon in the form of crystal oscillators.
Prior to his famous doctoral studies on magnetism he designed and perfected an extremely sensitive torsion balance for measuring magnetic coefficients. Variations on this equipment were commonly used by future workers in that area. Pierre Curie studied ferromagnetism, paramagnetism, and diamagnetism for his doctoral thesis, and discovered the effect of temperature on paramagnetism which is now known as Curie's law. The material constant in Curie's law is known as the Curie constant. He also discovered that ferromagnetic substances exhibited a critical temperature transition, above which the substances lost their ferromagnetic behaviour. This is now known as the Curie point.
Pierre worked with his wife Marie Curie in isolating polonium and radium. They were the first to use the term 'radioactivity', and were pioneers in its study. Their work, including Marie's celebrated doctoral work, made use of a sensitive piezoelectric electrometer constructed by Pierre and his brother Jacques.