Metastable Solid Solutions Formed by Metal Nanoparticles

Abstract

Metastable solid solutions of metals have been obtained using nano- and subnanoparticles. This study shows the effect of the size of atoms of a second element on the multiple increase in solubility and limiting concentration in the solvent, independently of the type of crystal lattice. As an example, the limiting solubility of lead (rPb = 0.935 nm) in niobium (rNb = 0.625 nm) is 23.0 at % and that of cadmium (rCd = 0.1727 nm)in niobium is 64.0 at %. Further, amorphization of the matrix metal occurs. Compared to metastable solid solutions with the equilibrium systems for which the Hume–Rothery rules work, alloys are formed from metals with different types of crystal lattices. In many cases, a 15% limit of the difference of the sizes of metal atoms is observed. There is a strong discrepancy in the valences of atoms and, in rare cases, in electronegativity. Using analysis of the attributes of the alloys prepared by sputtering of ultradisperse particles, the possibility of expanding the boundaries of the Hume–Rothery criteria should be noted for metastable alloys, in comparison to their equilibrium analogs, which indicates the possibility of deviation from the traditional forecasting the routine of preparation of the material.