The crystal structure of α-copper vanadate is characterized by a framework of oxygen ions arranged in a cubic close-packed (CCP) array, with both vanadium and copper ions occupying specific interstitial sites within this lattice. This structure is notable for featuring one of the rare instances of tetrahedrally coordinated copper.
Key Structural Features of α-Copper Vanadate
The fundamental arrangement of ions in α-copper vanadate is built upon a closely packed oxygen sublattice that provides the basic framework. Within this robust oxygen array, the metallic cations — vanadium and copper — are strategically positioned in interstitial voids, defining the unique structural characteristics of the compound.
Cation Coordination
The distinct coordination environments of the metal ions are crucial to understanding the properties of α-copper vanadate.
| Ion | Coordination Site | Occupation | Notes |
|---|---|---|---|
| Oxygen | Cubic Close-Packed (CCP) Array | Forms the primary lattice | Provides the foundational framework for the structure. |
| Vanadium | Octahedral | Fully Occupied | Each vanadium ion is surrounded by six oxygen ions. |
| Copper (1) | Octahedral | Partially Occupied | One type of copper site where the position is not always filled. |
| Copper (2) | Tetrahedral | Fully Occupied | The other copper site, where each copper ion is surrounded by four oxygen ions. |
Significance of Tetrahedrally Coordinated Copper
The presence of copper in a tetrahedral coordination environment is particularly noteworthy. While copper typically exhibits octahedral or square planar coordination in many compounds, tetrahedral coordination is much less common. This unique arrangement can significantly influence the material's electronic, magnetic, and optical properties, making α-copper vanadate an interesting subject for materials science research. Such rare coordination geometries often lead to unusual and desirable functionalities.
