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

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F17%3A00481166" target="_blank" >RIV/68081723:_____/17:00481166 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14740/17:00100047

Výsledek na webu

<a href="http://dx.doi.org/10.1088/1361-651X/aa86bf" target="_blank" >http://dx.doi.org/10.1088/1361-651X/aa86bf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1361-651X/aa86bf" target="_blank" >10.1088/1361-651X/aa86bf</a>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Modelling and Simulation in Materials Science and Engineering

ISSN

0965-0393

e-ISSN

—

Svazek periodika

25

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

40

Strana od-do

—

Kód UT WoS článku

000413837100001

EID výsledku v databázi Scopus

2-s2.0-85034606296