Effect of magnetism and light sp-dopants on chain creation in Ir and Pt break junctions

S. DI NAPOLI; A. THIESS; S. BLÜGEL; Y. MOKROUSOV

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Lugar: Londres; Año: 2014 vol. 26 p. 2953021 - 29530210

0953-8984

Applying the generalization of the model for chain formation in break-junctions [JPCM 24, 135501 (2012)], we study the effect of lightimpurities on the energetics and elongation properties of Pt and Ir chains. Our model enables us with a tool ideal for detailed analysis of impurity assisted chain formation, where zigzag bonds play animportant role. In particular we focus on H (s-like) and O (p-like)impurities and assume, for simplicity, that the presence of impurityatoms in experiments results in ..M-X-M-X-... (M: metal, X: impurity)chain structure in between the metallic leads. Feeding our model with material-specific parameters from systematic full-potential  first-principles calculations, we find that the presence of such impurities strongly affects the binding properties of the chains. We find that while both types of impurities enhance the probability of chains tobe elongated, the s-like impurities lower the chain´s stability. We also analyze the effect of magnetism and spin-orbit interaction on the growth properties of the chains.