TU Darmstadt / ULB / TUbiblio

Ca segregation to basal surface in Alpha-alumina

Kaplan, Wayne D. ; Müllejans, H. ; Rühle, M. ; Rödel, Jürgen ; Claussen, Nils :
Ca segregation to basal surface in Alpha-alumina.
[Online-Edition: http://dx.doi.org/10.1111/j.1151-2916.1995.tb08064.x]
In: Journal of the American Ceramical Society. 78 (1995), No. 10, S. 2841-2844, 78 (10) pp. 2841-2844.
[Artikel], (1995)

Offizielle URL: http://dx.doi.org/10.1111/j.1151-2916.1995.tb08064.x

Kurzbeschreibung (Abstract)

High-resolution transmission electron microscopy (HRTEM) and analytical electron microscopy (AEM) mere used to investigate the structure and chemistry of (0001) alpha-Al2O3/Al interfaces in melt-infiltrated polycrystalline alumina composites, HRTEM revealed an interfacial region different from both Al and alpha-Al2O3, with a structural width of 0.8 +/- 0.2 nm, AEM of the same interfaces revealed a Ca excess of Gamma = 2.5 +/- 0.5 Ca atoms per nm(2) (Ca/nm(2)). AEM of a basal twin boundary in the alpha-Al2O3 also revealed a Ca excess (Gamma = 1.0 +/- 0.5 Ca/nm(2)). Since the metal-ceramic interfaces mere the free surfaces of pores before melt infiltration, it can be concluded that Ca segregates to the basal surface of alumina, as well as to basal twin boundaries. Furthermore, the Ca at the free surfaces does not reside on only one cation plane, but is spread over 4 +/- 1 basal cation layers and forms an interfacial phase with a nominal composition of CaO . 6Al(2)O(3).

Typ des Eintrags: Artikel
Erschienen: 1995
Autor(en): Kaplan, Wayne D. ; Müllejans, H. ; Rühle, M. ; Rödel, Jürgen ; Claussen, Nils
Titel: Ca segregation to basal surface in Alpha-alumina
Sprache: Englisch
Kurzbeschreibung (Abstract):

High-resolution transmission electron microscopy (HRTEM) and analytical electron microscopy (AEM) mere used to investigate the structure and chemistry of (0001) alpha-Al2O3/Al interfaces in melt-infiltrated polycrystalline alumina composites, HRTEM revealed an interfacial region different from both Al and alpha-Al2O3, with a structural width of 0.8 +/- 0.2 nm, AEM of the same interfaces revealed a Ca excess of Gamma = 2.5 +/- 0.5 Ca atoms per nm(2) (Ca/nm(2)). AEM of a basal twin boundary in the alpha-Al2O3 also revealed a Ca excess (Gamma = 1.0 +/- 0.5 Ca/nm(2)). Since the metal-ceramic interfaces mere the free surfaces of pores before melt infiltration, it can be concluded that Ca segregates to the basal surface of alumina, as well as to basal twin boundaries. Furthermore, the Ca at the free surfaces does not reside on only one cation plane, but is spread over 4 +/- 1 basal cation layers and forms an interfacial phase with a nominal composition of CaO . 6Al(2)O(3).

Titel der Zeitschrift, Zeitung oder Schriftenreihe: Journal of the American Ceramical Society. 78 (1995), No. 10, S. 2841-2844
Band: 78
(Heft-)Nummer: 10
Fachbereich(e)/-gebiet(e): Fachbereich Material- und Geowissenschaften > Materialwissenschaften > Nichtmetallisch-Anorganische Werkstoffe
FB Materialwissenschaft (aufgegangen in FB11)
Fachbereich Material- und Geowissenschaften > Materialwissenschaften
Fachbereich Material- und Geowissenschaften
Hinterlegungsdatum: 19 Nov 2008 15:58
Offizielle URL: http://dx.doi.org/10.1111/j.1151-2916.1995.tb08064.x
ID-Nummer: 10.1111/j.1151-2916.1995.tb08064.x
Export:

Optionen (nur für Redakteure)

Eintrag anzeigen Eintrag anzeigen