Crystal growth
US4211600A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1975 |
| Grant date | Jul 8, 1980 |
| Priority date | — |
| Expiry date | Dec 3, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S117/91
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Thin strip crystals are grown by pulling the growing crystal from the melt, through a thin slit, the walls of which are not wetted by the melt. The stability of growth at the edges of the strip is achieved by maintaining the pressure of the melt adjacent the interface between crystal and melt above a critical level which is such as to cause the meniscus of the melt to be convex on all sides of the growing crystal. The critical pressure is defined as EQU 2S/b+.sqroot.2Szg where PA1 S is the surface tension of the crystallizable material PA1 b is the thickness of the slit PA1 z is the density of the melt PA1 g is the acceleration due to gravity; and the depth of the slit is at least (2S/zg).sup.1/2, preferably (32S/zg).sup.1/2 to ensure that a pressure exceeding the critical pressure can be developed and maintained without the liquid spilling out of the slit. The walls of the slit can be parallel or divergent in the direction in which the crystal is pulled, this divergence being necessary with certain materials. An arrangement is disclosed containing a head of the melt for creating the required pressure. An alternative arrangement is disclosed in which actuating devices, such as hydr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.