Počet záznamů: 1

Segregation of sp-impurities at grain boundaries and surfaces: comparison of fcc cobalt and nickel

SYSNO ASEP	0481166
Druh ASEP	J - Článek v odborném periodiku
Zařazení RIV	J - Článek v odborném periodiku
Poddruh J	Článek ve WOS
Název	Segregation of sp-impurities at grain boundaries and surfaces: comparison of fcc cobalt and nickel
Tvůrce(i)	Všianská, Monika (UFM-A) Vémolová, H. (CZ) Šob, Mojmír (UFM-A)_{RID, ORCID}
Celkový počet autorů	3
Číslo článku	085004
Zdroj.dok.	Modelling and Simulation in Materials Science and Engineering. - : Institute of Physics Publishing - ISSN 0965-0393 Roč. 25, č. 8 (2017)
Poč.str.	40 s.
Jazyk dok.	eng - angličtina
Země vyd.	GB - Velká Británie
Klíč. slova	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
Vědní obor RIV	BM - Fyzika pevných látek a magnetismus
Obor OECD	Condensed matter physics (including formerly solid state physics, supercond.)
CEP	GA16-24711S GA ČR - Grantová agentura ČR
Institucionální podpora	UFM-A - RVO:68081723
UT WOS	000413837100001
EID SCOPUS	85034606296
DOI	10.1088/1361-651X/aa86bf
Anotace	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.
Pracoviště	Ústav fyziky materiálu
Kontakt	Yvonna Šrámková, sramkova@ipm.cz, Tel.: 532 290 485
Rok sběru	2018

Počet záznamů: 1