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AuAl is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Au is bonded in a body-centered cubic geometry to eight equivalent Al atoms. All Au–Al bond lengths are 2.79 Å. Al is bonded in a body-centered cubic geometry to eight equivalent Au atoms.
EuAu2Al2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Eu is bonded in a 12-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.40 Å) and four longer (3.46 Å) Eu–Au bond lengths. There are four shorter (3.41 Å) and four longer (3.47 Å) Eu–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded in a 5-coordinate geometry to four equivalent Eu and five Al atoms. There are one shorter (2.55 Å) and four longer (2.63 Å) Au–Al bond lengths. In the second Au site, Au is bonded to four equivalent Eu and four equivalent Al atoms to form distorted AuEu4Al4 tetrahedra that share corners with twelve equivalent AlEu4Au4 tetrahedra, edges with two equivalent AlEu4Au4 tetrahedra, edges with four equivalent AuEu4Al4 tetrahedra, and faces with four equivalent AuEu4Al4 tetrahedra. All Au–Al bond lengths are 2.61 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 5-coordinate geometry to four equivalent Eu and five Au atoms. In the second Al site, Al is bonded to four equivalent Eu and four equivalent Au atoms to form AlEu4Au4 tetrahedra that share corners with twelve equivalent AuEu4Al4 tetrahedra, edges with two equivalent AuEu4Al4 tetrahedra, edges with four equivalent AlEu4Au4 tetrahedra, and faces with four equivalent AlEu4Au4 tetrahedra.
AuAl is Modderite structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Au sites. In the first Au site, Au is bonded in a 6-coordinate geometry to six Al atoms. There are a spread of Au–Al bond distances ranging from 2.64–2.76 Å. In the second Au site, Au is bonded in a 6-coordinate geometry to six Al atoms. There are a spread of Au–Al bond distances ranging from 2.62–2.76 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 6-coordinate geometry to six Au atoms. In the second Al site, Al is bonded in a 6-coordinate geometry to six Au atoms.
UAu2Al2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. U is bonded in a 12-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.31 Å) and four longer (3.38 Å) U–Au bond lengths. There are four shorter (3.29 Å) and four longer (3.41 Å) U–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent U and four equivalent Al atoms to form distorted AuU4Al4 tetrahedra that share corners with twelve equivalent AlU4Au4 tetrahedra, edges with two equivalent AlU4Au4 tetrahedra, edges with four equivalent AuU4Al4 tetrahedra, and faces with four equivalent AuU4Al4 tetrahedra. All Au–Al bond lengths are 2.58 Å. In the second Au site, Au is bonded in a 5-coordinate geometry to four equivalent U and five Al atoms. There are one shorter (2.44 Å) and four longer (2.57 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent U and four equivalent Au atoms to form AlU4Au4 tetrahedra that share corners with twelve equivalent AuU4Al4 tetrahedra, edges with two equivalent AuU4Al4 tetrahedra, edges with four equivalent AlU4Au4 tetrahedra, and faces with four equivalent AlU4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent U and five Au atoms.
Ce(AuAl)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ce is bonded in a 8-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.38 Å) and four longer (3.42 Å) Ce–Au bond lengths. There are four shorter (3.39 Å) and four longer (3.43 Å) Ce–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Ce and four equivalent Al atoms to form distorted AuCe4Al4 tetrahedra that share corners with twelve equivalent AlCe4Au4 tetrahedra, edges with two equivalent AlCe4Au4 tetrahedra, edges with four equivalent AuCe4Al4 tetrahedra, and faces with four equivalent AuCe4Al4 tetrahedra. All Au–Al bond lengths are 2.59 Å. In the second Au site, Au is bonded in a 5-coordinate geometry to four equivalent Ce and five Al atoms. There are one shorter (2.51 Å) and four longer (2.61 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Ce and four equivalent Au atoms to form distorted AlCe4Au4 tetrahedra that share corners with twelve equivalent AuCe4Al4 tetrahedra, edges with two equivalent AuCe4Al4 tetrahedra, edges with four equivalent AlCe4Au4 tetrahedra, and faces with four equivalent AlCe4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Ce and five Au atoms.
ThAu2Al2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Th is bonded in a 12-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.37 Å) and four longer (3.41 Å) Th–Au bond lengths. There are four shorter (3.36 Å) and four longer (3.44 Å) Th–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Th and four equivalent Al atoms to form distorted AuTh4Al4 tetrahedra that share corners with twelve equivalent AlTh4Au4 tetrahedra, edges with two equivalent AlTh4Au4 tetrahedra, edges with four equivalent AuTh4Al4 tetrahedra, and faces with four equivalent AuTh4Al4 tetrahedra. All Au–Al bond lengths are 2.60 Å. In the second Au site, Au is bonded in a 5-coordinate geometry to four equivalent Th and five Al atoms. There are one shorter (2.51 Å) and four longer (2.59 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Th and four equivalent Au atoms to form AlTh4Au4 tetrahedra that share corners with twelve equivalent AuTh4Al4 tetrahedra, edges with two equivalent AuTh4Al4 tetrahedra, edges with four equivalent AlTh4Au4 tetrahedra, and faces with four equivalent AlTh4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Th and five Au atoms.
Nd(AuAl)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Nd is bonded in a 8-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.40 Å) and four longer (3.41 Å) Nd–Au bond lengths. There are four shorter (3.39 Å) and four longer (3.43 Å) Nd–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Nd and four equivalent Al atoms to form distorted AuNd4Al4 tetrahedra that share corners with twelve equivalent AlNd4Au4 tetrahedra, edges with two equivalent AlNd4Au4 tetrahedra, edges with four equivalent AuNd4Al4 tetrahedra, and faces with four equivalent AuNd4Al4 tetrahedra. All Au–Al bond lengths are 2.60 Å. In the second Au site, Au is bonded in a 5-coordinate geometry to four equivalent Nd and five Al atoms. There are one shorter (2.51 Å) and four longer (2.61 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Nd and four equivalent Au atoms to form distorted AlNd4Au4 tetrahedra that share corners with twelve equivalent AuNd4Al4 tetrahedra, edges with two equivalent AuNd4Al4 tetrahedra, edges with four equivalent AlNd4Au4 tetrahedra, and faces with four equivalent AlNd4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Nd and five Au atoms.
SrAu2Al2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sr is bonded in a 8-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.45 Å) and four longer (3.47 Å) Sr–Au bond lengths. There are four shorter (3.46 Å) and four longer (3.48 Å) Sr–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Sr and four equivalent Al atoms to form distorted AuSr4Al4 tetrahedra that share corners with twelve equivalent AlSr4Au4 tetrahedra, edges with two equivalent AlSr4Au4 tetrahedra, edges with four equivalent AuSr4Al4 tetrahedra, and faces with four equivalent AuSr4Al4 tetrahedra. All Au–Al bond lengths are 2.62 Å. In the second Au site, Au is bonded in a 9-coordinate geometry to four equivalent Sr and five Al atoms. There are one shorter (2.58 Å) and four longer (2.65 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Sr and four equivalent Au atoms to form distorted AlSr4Au4 tetrahedra that share corners with twelve equivalent AuSr4Al4 tetrahedra, edges with two equivalent AuSr4Al4 tetrahedra, edges with four equivalent AlSr4Au4 tetrahedra, and faces with four equivalent AlSr4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Sr and five Au atoms.
Sm(AuAl)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sm is bonded in a 8-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.38 Å) and four longer (3.39 Å) Sm–Au bond lengths. There are four shorter (3.37 Å) and four longer (3.43 Å) Sm–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Sm and four equivalent Al atoms to form distorted AuSm4Al4 tetrahedra that share corners with twelve equivalent AlSm4Au4 tetrahedra, edges with two equivalent AlSm4Au4 tetrahedra, edges with four equivalent AuSm4Al4 tetrahedra, and faces with four equivalent AuSm4Al4 tetrahedra. All Au–Al bond lengths are 2.60 Å. In the second Au site, Au is bonded in a 5-coordinate geometry to four equivalent Sm and five Al atoms. There are one shorter (2.49 Å) and four longer (2.59 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Sm and four equivalent Au atoms to form distorted AlSm4Au4 tetrahedra that share corners with twelve equivalent AuSm4Al4 tetrahedra, edges with two equivalent AuSm4Al4 tetrahedra, edges with four equivalent AlSm4Au4 tetrahedra, and faces with four equivalent AlSm4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Sm and five Au atoms.
Atomic Force Microscopy (AFM), in conjunction with Peak Force Kelvin Probe Force Microscopy (PF-KPFM) and Peak Force Scanning Spreading Resistance Microscopy (PF-SSRM), was used to assess changes on thin metal films that underwent accelerated aging. The AFM technique provides a relatively easy, non-destructive methodology that does not require high-vacuum facilities to obtain nanometer-scale spatial resolution of surface chemistry changes. Surface morphology, roughness, contact potential difference, and spreading resistance were monitored to qualitatively identify effects of aging-morphology changes and oxidation of Au, Al, Cu thin film standards as well as diffusion of CuAu and AlAu thin film stacks at 65C under dried nitrogen flow conditions. AFM PF-KPFM and PF-SSRM modes have been exercised, refined and have proven to be viable and necessary early aging detection tools.