Edmund Clifton Stoner

Edmund Clifton Stoner (born October 2, 1899 in Esher, Surrey , England , † December 27, 1968 in Leeds , England) was an English theoretical physicist . He is best known for his work on the origin of magnetism . These include the collective electron theory and the Stoner criterion . He also played a role in the establishment of the periodic table from the older quantum theory.

Life

Stoner lost his father, who was a professional cricket player, at an early age and could only finance his school attendance (Bolton Grammar School) by winning scholarships. Because of health problems (in 1919 he diagnosed himself with diabetes) he was exempt from military service in World War I. He began his studies in Cambridge in 1918 , where he received his bachelor's degree in 1921. After graduating, he worked at the Cavendish Laboratory on X-ray Absorption in Matter under Ernest Rutherford . He was less happy with his experimental work (and Rutherford) (but he received a thorough knowledge of spectroscopy and its language), but he was enthusiastic about Niels Bohr's atomic theory and attended Bohr's lectures in Cambridge in 1922. Stoner arrived simultaneously and independently by John David Main Smith on essential findings about the foundation of the periodic table via the older Bohr quantum theory. This 1924 work is probably his most significant work and in a way it anticipated the Pauli principle . She also had a direct influence on Pauli in the development of the Pauli principle and was otherwise well received by Louis de Broglie and Arnold Sommerfeld . Sommerfeld quickly picked it up in his own research. Bohr was more cautious and could not quite detach himself from his own theory, even if he saw Stoner's theory as progress and in the end adapted his configurations to those of Stoner and Main Smith. Stoner's doctoral supervisor Rutherford passed it on to theoretical physicist Ralph Howard Fowler , who urged Stoner to publish it. In contrast to Bohr's symmetrical shell structure, he recognized, like Main Smith, that completely different electron configurations occur in the lower shells than assumed by Bohr (in steps of 2, 2, 4 etc.) and that in each shell initially a lower shell made of 2 electrons (later s-orbital) was present. In the history of science, however, Stoner's contribution was largely forgotten for a long time.

He became a lecturer at the University of Leeds in 1924 , where he was appointed professor of theoretical physics in 1939. At the beginning he dealt with astrophysics , where he calculated the mass limit for white dwarfs in 1930 . However, he dedicated his main work to magnetism, beginning with the collective electron theory of ferromagnetism, which was developed from 1938 onwards .

With his student Erich Peter Wohlfarth , he developed the Stoner-Wohlfarth model of ferromagnetic single-domain nanoparticles and ensembles from these crystals in 1948.

Selected publications

• On the distribution of electrons among atomic levels. In: Philosophical Magazine. (6th series) Volume 48, 1924, pp. 719-736.
• The limiting density of white dwarf stars. In: Philosophical Magazine. (7th series) Volume 7, 1929, pp. 63-70.
• The equilibrium of dense stars. In: Philosophical Magazine. (7th series) Volume 9, 1930, pp. 944-963.
• Magnetism and atomic structure. Methuen, London 1926.
• Magnetism and matter. Methuen, London 1934.
• Collective electron ferromagnetism. In: Proceedings of the Royal Society of London . Series A, Volume 165, 1938, pp. 372-414.
• Collective electron ferromagnetism II. Energy and specific heat. In: Proceedings of the Royal Society of London. Series A, Volume 169, 1939, pp. 339-371.
• Collective electron ferromagnetism in metals and alloys. In: Journal de physique et le radium. (8th series) Vol. 12, 1951, pp. 372-388.

literature

• Eric Scerri : A Tale of Seven Scientists, and a New Philosophy of Science , Oxford University Press, New York, 2016

Individual evidence

1. ↑ Scerri, A tale of seven scientists, p. 144