Influence of metal-oxide interfaces on L1{sub 2} ordering in Cu{sub 3}Pd

Journal Article · Mon Sep 06 04:00:00 EDT 2004 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2004.06.021· OSTI ID:20634769

Mogck, S; Kooi, B J; Hosson, J Th.M. de

A strong influence of the polarity on the degree of L1{sub 2} order near interfaces between Cu{sub 3}Pd and MnO has been observed. In situ TEM annealing at various temperatures was performed to re-establish the L1{sub 2} ordering in Cu{sub 3}Pd alloy containing MnO precipitates. Subsequently, high-resolution transmission electron microscopy was used to analyze the long-range order in Cu{sub 3}Pd (L1{sub 2}) at parallel {l_brace}0 0 2{r_brace} and parallel {l_brace}1 1 1{r_brace} Cu{sub 3}Pd-MnO interfaces. Analyses of the polar {l_brace}1 1 1{r_brace} interfaces in the <1 1 0> and <1 1 2> projection show a gradual disappearance of L1{sub 2} order within the Cu{sub 3}Pd with decreasing distance to these interfaces. The interesting point is that the L1{sub 2} order dissolves over about 10 monolayers (MLs). In contrast, for the non-polar parallel {l_brace}0 0 2{r_brace} interface viewed along <1 0 0> no influence on the L1{sub 2} order and APB structure, even close to the interface could be observed. Analytical TEM analysis revealed a small enrichment of Pd at the {l_brace}1 1 1{r_brace} Cu{sub 3}Pd-MnO interface in the Cu{sub 3}Pd ML nearest to the interface. This phenomenon is not considered responsible for the interfacial disorder extending over such a large length scale. Physical effects that cause the disordering at the polar interface are discussed. The conclusion of the analysis is that the dipolar contribution to the internal energy acts as an initiation of disordering along the MnO/Cu{sub 3}Pd interface but that the configurational entropy determines the extension of the disordered area.

• OSTI ID: 20634769
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 15 Vol. 52; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
COPPER COMPOUNDS
ENTROPY
INTERFACES
INTERMETALLIC COMPOUNDS
MANGANESE OXIDES
PALLADIUM COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY