 Bimetallic nanocrystal

A bimetallic nanocrystal is a crystalline particle containing two metallic chemical elements, with important dimensions on the nanoscale. Its atoms may form an alloy, chemically ordered regions, a core surrounded by a shell or spatially separated domains. Composition alone does not determine which arrangement is present.

For example, a gold–silver particle can expose a surface composition different from its bulk average. That affects surface chemistry and interaction with light. Establishing its structure requires complementary evidence: electron microscopy can reveal morphology, elemental mapping can locate the elements, and diffraction can constrain the crystal structure. These measurements answer different questions rather than providing interchangeable particle descriptions.