Number of the records: 1
Segregation of sp-impurities at grain boundaries and surfaces: comparison of fcc cobalt and nickel
- 1.
SYSNO ASEP 0481166 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Segregation of sp-impurities at grain boundaries and surfaces: comparison of fcc cobalt and nickel Author(s) Všianská, Monika (UFM-A)
Vémolová, H. (CZ)
Šob, Mojmír (UFM-A) RID, ORCIDNumber of authors 3 Article number 085004 Source Title Modelling and Simulation in Materials Science and Engineering. - : Institute of Physics Publishing - ISSN 0965-0393
Roč. 25, č. 8 (2017)Number of pages 40 s. Language eng - English Country GB - United Kingdom Keywords local magnetic-moments ; total-energy calculations ; augmented-wave method ; solute segregation ; tilt boundaries ; embrittling potency ; alloying elements ; hcp metals ; basis-set ; 1st-principles ; grain boundary segregation ; strengthening/embrittling energy ; grain boundary magnetism ; ab initio calculations ; surface segregation Subject RIV BM - Solid Matter Physics ; Magnetism OECD category Condensed matter physics (including formerly solid state physics, supercond.) R&D Projects GA16-24711S GA ČR - Czech Science Foundation (CSF) Institutional support UFM-A - RVO:68081723 UT WOS 000413837100001 EID SCOPUS 85034606296 DOI 10.1088/1361-651X/aa86bf Annotation We perform systematic ab initio investigations of the segregation of 12 nonmagnetic sp-impurities (Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te) at the Sigma 5 (210) grain boundary (GB) and (210) free surface (FS) in fcc ferromagnetic cobalt and analyse their effect on structural, magnetic and mechanical properties, the results are compared with those obtained previously for nickel. It turns out that there is a slight enhancement of magnetization at the clean GB and FS with respect to bulk cobalt (4.7% and 17%, respectively). However, segregated sp-impurities sharply reduce this magnetization. As shown previously, in nickel most of the above impurities nearly destroy or substantially reduce the magnetic moments at the FS and, when segregated interstitially (i.e. Si, P, S, Ge, As, and Se), also at the GB, so that they provide atomically thin, magnetically dead layers, which may be very desirable in spintronics. The reduction of magnetic moments at the Sigma 5(210) GB in fcc ferromagnetic cobalt is, in absolute values, very similar to that in nickel. However, as the magnetic moment in bulk cobalt is higher, we do not observe magnetically dead layers here. Further, we find the preferred segregation sites at the Sigma 5(210) GB for the sp-impurities studied, and their segregation enthalpies and strengthening/embrittling energies with their decomposition into their chemical and mechanical components. It turns out that interstitially segregated Si is a GB cohesion enhancer, and interstitially segregated P, S, Ge, As, and Se and substitutionally segregated Al, Ga, In, Sn, Sb and Te are GB embrittlers in fcc cobalt. As there is essentially no experimental information on GB segregation in cobalt, most of the present results are theoretical predictions which may motivate future experimental work. Workplace Institute of Physics of Materials Contact Yvonna Šrámková, sramkova@ipm.cz, Tel.: 532 290 485 Year of Publishing 2018
Number of the records: 1