Open AccessMagnetism and atomic structure.—II. The constitution of the hydrogen-palladium system and other similar systems
Publication year - 1922
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1922.0042
Subject(s) - palladium , diamagnetism , magnetism , hydrogen , hydrogen atom , chemistry , paramagnetism , condensed matter physics , physics , magnetic field , organic chemistry , quantum mechanics , catalysis , alkyl
The present work is a continuation of that published in ‘Phil. Trans., A, vol. 214, pp. 109-146 (1914); A, vol. 215, pp. 79-103 (1915); A, vol. 220, pp. 247-289 (1920); ‘Roy. Soc. Proc.,' A, vol. 95, p. 58 (1918), and A, vol. 98, p. 264 (1921). It was believed that a magnetic examination of the properties of palladium black which had been charged with hydrogen would enable us to decide which of the proposed constitutions is the correct one. If the hydrogen were in the atomic state andfree , one might expect that the system would be more magnetic than uncharged palladium black, whether the assumed constitution of the hydrogen atom be that of Bohr or that proposed by the author. If the contained hydrogen were in the molecular form, either in the state of a gas or condensed to a liquid, since gaseous and liquid hydrogen are both diamagnetic, we should expect a diminution of the magnetic property of the system by a small amount, depending on the minute diamagnetic susceptibility of molecular hydrogen and the amount of gas occluded. Lastly, if the hydrogen enters into combination with the palladium, or is associated with the palladium so as to form a type of loose chemical compound, we should, in the light of previous knowledge of the effects of chemical combination on magnetic susceptibility, expect a change depending on the nature of the compound formed. It is impossible here to go into details regarding the vast amount of work which has been undertaken to solve the problem of gaseous occlusion. Reference is made to the General Discussion held by the Faraday Society on the subject. It will be convenient to summarise here the diverse views at present held as to the nature of the complex process of occlusion. These have been given by A. W. Porter under the following six heads:— (1) Chemical combination of the gas with the metal. (2) Simple solid solution, either separately or in conjunction with (1). (3) Two solid solutions in contiguous phases. (4) Solution accompanied by surface adsorption. (5) Surface condensation under molecular forces unaccompanied by solution. (6) Simple inclusion of the gas in the interstices of the metal.