LavesPhasen

Laves phases are a group of intermetallic compounds with the general stoichiometry AB2. They are characterized by a specific crystal structure and are formed between elements with particular atomic size ratios. Typically, the atomic radius of element A is about 1.2 to 1.6 times that of element B. This size difference is crucial for the formation of the characteristic Laves phase structure.

The crystal structures of Laves phases are based on close-packed arrangements of the larger A atoms, with the smaller B atoms occupying specific interstitial sites. There are three main types of Laves phases, distinguished by their stacking sequence of close-packed layers: the cubic C15 phase (MgCu2 type), the hexagonal C14 phase (MgZn2 type), and the less common hexagonal C36 phase (MgNi2 type). The specific structure formed depends on the electronic properties and bonding characteristics of the constituent elements.

Laves phases are found in numerous binary and ternary alloy systems involving a wide range of elements, including transition metals, rare-earth elements, and main group elements. They are known for their high melting points, good mechanical strength, and often exhibit useful magnetic or electrical properties. Their stability and properties make them relevant in various applications, such as high-temperature alloys, magnets, and structural materials. The study of Laves phases is important in materials science for understanding phase diagrams, predicting alloy behavior, and designing new functional materials.