Cabrera, Blas

(b. Lanzarote, Canary Islands, Spain, 20 May 1878; d. Mexico City, Mexico, 1 August 1945),

physics.

Cabrera obtained his licenciatura in sciences in 1898 and his Ph.D. with honors in 1901 at the University of Madrid. He became an assistant professor there and in 1905 was appointed professor of electricity and magnetism.

Early in his career Cabrera published several papers on the properties of electrolytes. He also began working on the magnetic properties of matter, which later became his major interest. As a result of his papers, in 1910 Cabrera was appointed director of the newly established Spanish Physical Research Institute. From 1910 to 1912 he worked with Pierre Weiss, then at the Polytechnical School of Zurich. This period was crucial in Cabrera’s scientific career: most of his research thereafter dealt with the study of weakly magnetic substances.

From 1912 on, he carried out intensive research in magnetochemistry. He tried to provide an experimental check on Weiss’s magneton theory, which he mentions in almost every paper. A result of this work was a Rockefeller Foundation grant to build a new National Institute of Physics and Chemistry. Appointed its director in 1932, Cabrera encouraged teamwork between physicists and chemists, and work in magnetochemistry proceeded vigorously.

Cabrera published over 110 papers between 1912 and 1934. He contributed to establishment of Hundand Van Vleck’s molecular field, established the variation of the atomic magnetic moment versus atomic number, modified the Curie-Weiss law for the rare earths, derived an equation for the atomic magnetic moment including the temperature effect and improved many experimental devices he worked with. Some of his magnetic susceptibility measurements have not been improved upon.

In 1936 Cabrera, with Cotton, started a laboratory for magnetic research in Paris. From 1941 to 1945 he was a professor at the University of Mexico. At his death, he had published over 150 papers.

BIBLIOGRAPHY

1.Original Works. Cabrera’s most important papers include “Sobre la relación que liga la susceptibilidad con la permeabilidad magnetica,” in Anales de la Sociedad españtola de fisca y quimica. 3 (1905), 34–35; “Sobre la relación del magnetismo permanente con la lemperatura,” ibid. 5 (1907), 152–168, 214–222; “La teoria de los magnetones y la magnetoquimica de los compuestos férrieos,” ibid.9 (1911), 316–344. 394–430, written with E. Moles; “Magnetoquimica de los compuestos de hierro.” ibid., 11 (1913), 398–419, written with E. Moles; “Instalación para la medida de la susceptibilidad de los cuerpos fuertcmente paramagnéticos,” ibid. 12 (1914), 512–525; “La magnetoquimica de las sales de cobre y la teoria del magnetón,” ibid., 373, written with E. Moles; “La magnetoquimica de los compuestos de niquel y la teoria del magnetón.” ibid., 131–142, written with E. Moles and J. Guzman; “La magnetoquimica de las sales de cobalto y la teoria de los magnetones.” ibid. 14 (1916), 357–373, written with E. Jimeno and M. Marquina; “Magnetoquimica de los compuestos del cromo,” ibid. 15 (1917), 199–209, written with M. Marquina; “Magnétochimie.” in Journal de chimie physique, 16 (1918), 442–460; “El paramagnetismo de lassales sólidas y la teoria del magnetón,” in Anales de las Sociedad española de fisica y quimica, 16 (1918), 436– 449;“La magnétoehimie des sels de manganèse,” in Journal de chimie physique. 16 (1918), 11–20, written with E. Moles and M. Marquina: “La magnetoquimica de la sales cromosas y oxicrómieas.” in Anales de la Sociedad española de fisica y quimica, 17 (1919), 149–167, written with S. Piñ a;“Variación de la consúme magnética del catión oxieró micopor la acción del ácido sulfúrico,” ibid., 20 (1922). 175–181, written with S. Piña: “Los magnetones de Weiss y de Bohry la constitución del átomo.” ibid. 21 (1923), 505–526, “Laconsume Δ de la ley de Curie modificada,” ibid., 22 (1924), 463–475: “Les terres rares et la question du magnéton.” Comptes rendus de l’Academie des Sciences, 180 (1925), 668–680; “Variación del paramagnetismo con la temperatura.” in Anales de la Sociedad española de fisica y quimica, 24 (1926). 297–317, written with J. Palacios; “Sur le paramagnétisme des families du palladium et du platine,” in Comptes rendus de l’Academie des Sciences, 185 (1927), 414, written with A. Duperier; “Sobre la teoria general de la propiedades magnéticas de la materia,” in Anales de la Sociedad española de fisica v quimica. 26 (1928), 50–71: “Valor del magnetón de Weiss deducido de los cuerpos paramagnéticos.” ibid., 28 (1930). 431–447; “Diamagnétisnie et température.” in Comptes rendus de l’Académic dessciences, 197 (1933), 379, written with H. Fahlenbrach: “Diamagnetismus von Wasser bei verschiedenen Temperaturen. I,” in zeitschrift für Physik, 82 (1933). 759, written with H. Fahlenbrach: “Über den Diamagnelismus desflüssigen und festen schweren Wassers und seinen Temperaturver lauf.” in Die Naturwissenschaften, 22 (1934), 417- 424, written with H. Fahlenbrach; “Über den Diamagnetismus organischer Verbindungen im Hinblick auf den Einfluss von Temperatur und Konstitution. II,” in Zeitschrift für Physik, 89 (1934), 682–694, written with H. Fahlenbrach; “Magnetische Untersuchung der gegenseitigen Beeinflussung von Kaliumjodid und Wasser in der Lösung,” ibid., 166–175, written with H. Fahlenbrach; “Further Results on the Magnetism of Chlorides of the Palladium and Platinum Triads of Elements,” in Proceedings of the Physical Society (London), 51 (1939), 845, written with A. Duperier; “Sur le paramagnétisme des terres rares,” Journal de chimie physique, 36 (1939), 273; “Diamagnétisme et structure moléculaire,” ibid., 38 (1941), I; and “Les susceptibilités diamagnétiques des alcools butyliques,” Comptes rendus de l’Académie des sciences, 213 (1941), 108, written with H. Colson.

II.Secondary Literature. See C. E. Hodgman, ed., Handbook of Physics and Chemistry, 37th ed. (Cleveland, Ohio, 1955), p. 2392: and A. H. Morrish, The Physical Principles of Magnetism (New York, 1965), p. 69.

Manuel Puigcerver