Hume-Rothery, William

Hume-Rothery, William (1899-1968) founded the Department of Metallurgy (now the Department of Materials) at Oxford University in the mid-1950s. HR, as he was known at Oxford, was the author of many books on metallurgy. One of his hooks, Electrons, Atoms, Metals, and Alloys, is a dialogue between an older metallurgist and a younger scientist. 

Understanding alloys in terms of electron theory. The band theory of solids had no impact on the thinking of metallurgists until the early 1930s, and the link which was eventually made was entirely due to two remarkable men - William Hume-Rothery in Oxford and Harry Jones in Bristol, the first a chemist by education and the second a mathematical physicist. 

Figure 3.28. William Hume-Rothery as a young man (courtesy Mrs. Jennifer Moss).

Pettifor, D.G. (2000) William Hume-Rothery his life and science, in The Science of Alloys for the list Century A Hume-Rothery Symposium Celebration, eds. Turchi, P. et a . (TMS, Warrendale). 

Most treatments, even when intended for materials scientists, of these competing forms of quantum-mechanical simplification are written in terms accessible only to mathematical physicists. Fortunately, a few translators , following in the tradition of William Hume-Rothery, have explained the essentials of the various approaches in simple terms, notably David Pettifor and Alan Cottrell (e.g., Cottrell 1998), from whom the formulation at the end of the preceding paragraph has been borrowed. 

The circumstances under which intermetallics form were elucidated by the British metallurgist William Hume-Rothery (1899-1968) for compounds between the noble metals and the elements to their right in the periodic table (Hume-Rothery, 1934 Reynolds and Hume-Rothery, 1937). These are now applied to all intermetaUic compounds, in general. The converse to an intermetaUic, a solid solution, is only stable for certain valence-electron count per atom ratios, and with minimal differences in the atomic radii, electronegativities, and crystal structures (bonding preferences) of the pure components. For example, it is a mle-of-thumb that elements with atomic radii differing by more than 15 percent generally have very little solid phase miscibility. 

An interesting area still under debate in the field of metallurgy is the consequences of Fermi surface topology on the phase equilibria in alloy systems. Elucidation of the connection between these two, seemingly unrelated, features started with the work of William Hume-Rothery, who reported that the critical-valence electron to atom ratios. 

In contrast to interstitial defects, the replacement of lattice atoms with dopant species is referred to as substitutional disorder. Since this type of displacement involves extensive diffusion of solvent and solute atoms, a number of requirements must be satisfied. These are known as the William Hume-Rothery Rulest ... 

William Hume-Rothery (1899-1968), ODNB, on whom G. V. Raynor, Biog. Mem. Roy. Soc., 1969, 15, 109 W. Hume-Rothery, The Metallic State, Electrical Properties and Theories, Clarendon Press, Oxford, 1931, and The Structure of Metals and Alloys, Institute of Metals, London, 1936 ... 

Hume-Rothery rules A set of empirical rules put forward in 1926 by the British metallurgist William Hume-Rothery (1899-1968) to describe how one metal dissolves in another metal. He found that one metallic element wUl not dissolve in another if the difference in their atomic radii Is greater than 15 per cent or if the electronegativities of the two elements differ substantially. Also, a metal with a lower valency is more likely to dissolve In one with a higher valency, than vice versa. These rules were subsequently justified by the quantum theory of electrons in solids. 

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