At the Sorbonne she met and married another instructor, Pierre Curie. Together they studied radioactive materials, particularly the uranium pitchblende ore, which had the curious property of being more radioactive than the uranium extracted from it. By 1898 they deduced a logical explanation: that the pitchblende contained traces of some unknown radioactive component which was far more radioactive than uranium; thus on December 26th Marie Curie announced the existence of this new substance.
Over several years of unceasing labour they refined several tons of pitchblende, progressively concentrating the radioactive components, and eventually isolated initially the chloride salts (refining radium chloride on April 20, 1902) and then two new chemical elements. The first they named polonium after Marie's native country, and the other was named radium from its intense radioactivity. Maria Skłodowska Curie Nobel Prize Diploma
In 1903 she became the first woman in France to complete her doctorate.
Together with Pierre Curie and Henri Becquerel, she was awarded the Nobel Prize in Physics, 1903: "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel". She was the first woman to be awarded a Nobel Prize. Eight years later, she received the Nobel Prize in Chemistry, 1911 "in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element". In an unusual move, Curie intentionally did not patent the radium isolation process, instead leaving it open so the scientific community could research unhindered. Just one month after accepting her 1911 Nobel Prize, Marie was hospitalized with depression and kidney trouble.
She was the first person to win or share two Nobel Prizes. She is one of only two people who has been awarded a Nobel Prize in two different fields, the other being Linus Pauling. As of October 2005, she remains the only woman to win two Nobel prizes.
After her husband's death, she supposedly had an affair with physicist Paul Langevin, a married man who had left his wife, which resulted in a press scandal, exacerbated by her academic opponents in order to damage her credibility. Despite her fame as an honored scientist working for France, the public's attitude to the scandal tended towards xenophobia — she was a foreigner, from an unknown land (Poland was still referred to as a geographical area, under the Russian Tsar), an area known to have a significant Jewish population (Marie was an atheist, raised as a Catholic, even born in a gentry family [ Dołęga-Sklodowski], but that didn't seem to matter). France at the time was still reeling from the effects of the Dreyfus affair etc, so the scandal's effect on the public was all the more acute. It is a strange coincidence that Paul's grandson Michel later married her granddaughter Hélène Langevin-Joliot.
During World War I, she pushed for the use of mobile radiography units for the treatment of wounded soldiers. These units were powered using tubes of radium emanation, a colorless, radioactive gas given off by radium, later to be identified as radon. Marie personally provided the tubes, derived from the radium she purified. Promptly after the war started, she donated her and her husband's gold Nobel Prize Medals for the war effort.
In 1921, she toured the United States, where she was welcomed triumphantly, to raise funds for research on radium.
In her later years, she was disappointed by the myriad physicians and makers of cosmetics who used radioactive material without precautions.
Her death near Sallanches in 1934 was from aplastic anemia, almost certainly due to her massive exposure to radiation in her work, much of which was carried out in a shed with no proper safety measures being taken, as the damaging effects of hard radiation were not generally understood at that time. She was known to carry test tubes full of radioactive isotopes in her pocket, and to store them in her desk drawer, resulting in massive exposure to radiation. She was known to remark on the pretty blue-green light the metals gave off in the dark. Historical 20 000 złoty banknote of Poland with face of Maria Skłodowska Curie
Her eldest daughter, Irène Joliot-Curie, won a Nobel Prize for Chemistry in 1935.