Related Experiment Video
Updated: Jun 1, 2026
08:15
Synthesis of Nine-atom Deltahedral Zintl Ions of Germanium and their Functionalization with Organic Groups
Published on: February 11, 2012
Pd(2.28(1))Zn(10.37(1))Al(0.35(1)), a ternary γ-brass-type structure
Srinivasa Thimmaiah1, Gordon J Miller
1Department of Chemistry and Ames Laboratory, Iowa State University, Ames, IA 50011, USA.
Summary
This study details the upper limit of aluminum substitution in palladium-zinc alloys, specifically Pd(2.28)Zn(10.37)Al(0.35). The findings reveal aluminum atoms occupy specific sites within the complex 26-atom cluster structure.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Crystallography
Background:
- The γ-brass phase in palladium-zinc systems is known for its complex cubic structure.
- Understanding the limits and sites of elemental substitution is crucial for tailoring alloy properties.
Purpose of the Study:
- To determine the maximum solubility of aluminum (Al) in the palladium-zinc (Pd-Zn) γ-brass phase.
- To elucidate the crystallographic sites occupied by substituted aluminum atoms within the Pd-Zn structure.
Main Methods:
- Single-crystal X-ray diffraction was used to analyze the crystal structure.
- Compositional analysis confirmed the stoichiometry of the palladium zinc aluminum (Pd2.28Zn10.37Al0.35) phase.
Main Results:
- The compound Pd(2.28)Zn(10.37)Al(0.35) represents the highest observed aluminum substitution level in the Pd-Zn γ-brass phase.
- The substituted Al atoms were found to occupy specific positions within the 26-atom cluster framework, namely the inner tetrahedron (IT) and cuboctahedron (CO) sites.
Conclusions:
- Aluminum can substitute into the cubic γ-brass Pd(2+x)Zn(11-x) phase up to a defined limit.
- The precise location of Al atoms within the IT and CO sites of the cluster structure provides insights into the bonding and stability of this complex intermetallic compound.
More Related Videos
Related Concept Videos
02:37Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:57Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
02:54Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...