BridgmanStockbargerVerfahren

The Bridgman-Stockbarger method is a directional solidification technique used to grow single crystals from a melt. It combines Percy W. Bridgman’s early work on temperature gradients with later refinements by Stockbarger. The approach exploits a controlled axial temperature gradient in a sealed container to promote unidirectional solidification, typically starting from a seed crystal or a cold end and advancing the solid-liquid interface along the gradient.

In practice, the material is placed in a quartz ampoule or crucible and heated to create a melt. A well-defined temperature gradient is established along the length of the container, so that the solidification front moves in a chosen direction as the material is translated through the gradient or as the gradient is adjusted. A seed crystal at the appropriate end can direct the crystallographic orientation of the grown crystal. Growth rate, gradient steepness, and translation speed determine crystal quality, defect density, and diameter.

The method has been applied to a wide range of materials, including elemental semiconductors such as silicon and germanium, compound semiconductors like gallium arsenide, and certain oxides and intermetallics. It is valued for producing relatively large single crystals with uniform properties and for its simplicity and compatibility with sealed-container processing. Limitations include slow growth rates, size constraints set by the equipment and crucible, and potential contamination from crucible materials or dissolved impurities. While many newer techniques exist, the Bridgman-Stockbarger method remains a foundational tool in crystal growth research and industrial crystal production.