Marriage, children and joint research
As she neared the end of her doctorate in 1924 she was asked to teach the precise laboratory techniques required for radiochemical research to a young chemical engineer called
Frédéric Joliot. In 1926 they were married (the couple both hyphenated their surnames). 11 months later, their daughter
Hélène, who herself was to become an internationally acclaimed physicist, was born and 5 years after that, in 1932, a son,
Pierre (named after Irène's father).
From 1928 Irène and Frédéric combined their research interests on the study of atomic nuclei. Though their experiments identified both the positron and the neutron they failed to interpret the significance of the results and the discoveries were later claimed by C.D. Anderson and James Chadwick respectively. These discoveries would have secured greatness indeed as together with J.J. Thompson’s discovery of the electron (in 1897) they finally replaced Dalton’s theory of atoms being solid spherical particles.
Finally, in 1934 they made the discovery that sealed their place in scientific history. Building on the work of Marie and Pierre, who had isolated naturally occurring radioactive elements, Irène and Frédéric realised the alchemist’s dream of turning one element into another, creating radioactive nitrogen from boron and then radioactive isotopes of phosphorus from aluminium and silicon from magnesium. By now the application of radioactive materials for use in medicine was growing and this discovery lead to an ability to create radioactive materials quickly, cheaply and plentifully. The Nobel Prize for chemistry in 1935 brought with it fame and recognition from the scientific community and Irène was awarded a professorship at the Faculty of Science.
Irène’s group pioneered research into radium nuclei that lead a separate group of German physicists to discover nuclear fission; the splitting of the nucleus itself and the vast amounts of energy emitted as a result.