Study on the addition of nonmetal interstitial atoms to the yttrium lattice: formation of YB_x, YC_x and YN_x alloys

Abstract

Yttrium is a rather rare and reactive met al. Due to these characteristics it absorbs important quantities of light atoms in its void spaces. Here, we present a study where B, C and N atoms are gradually incorporated into the octahedral interstices of Y. The idea is to model, by first‐principles calculations in a supercell approach, several stages of nonmetal assimilation in the yttrium lattice. In this case to develop YBx, YCx and YNx alloys. This study is limited to the cubic close‐packed stacking of Y and chemical compositions in the 0 ≤ x ≤ 1 range. We found that the studied alloys become thermodynamically favored. The cohesive energies improve with the addition of the nonmetal atoms. Besides, the cell volume and the bulk modulus vary differently for each kind of added atom. We come upon the fact that the ratio between cohesive energy and cell volume is strikingly better for YNx. We conclude that these alloys permit a remarkable degree of modulation in their properties and electronic structures by means of chemical composition. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

First-principles calculations of the structural, elastic, vibrational and electronic properties of YB6 compound under pressure

“…They reported an increase in Young's modulus of 87 GPa, 125 GPa and 160 GPa; for YB, YC, and YN, respectively. As a consequence, the Y-Y bond lengths with C remains constants a e-mail: mromero@ciencias.unam.mx essentially; while, a slight increase or contracting in these bond lengths is observed when B or N is incorporated [6]. For YB x with x = 4.0, Zhou et al reported 427 GPa [5].…”

Multi-functional magnesium alloys containing interstitial oxygen atoms

“…In this type of Mg-O alloy, the elastic modulus increases to a value approximately 10% greater than that of pure Mg ( Table S2 ). It is hypothesized that the incorporation of nonmetal atoms in the interstitial spaces of magnesium may increase the Mg-O ionic bonding character and average Mg-Mg interatomic distance, which enhances the stiffness of magnesium 28 . The yield stress of the Mg-O alloy (~73 MPa) is also three times higher than that of pure Mg ( Fig.…”