Abstract: The invention is a method for sharpening opposed edges of a monocrystalline ribbon. The method consists of suspending a monocrystalline body of a material such as alpha-alumina in the form of a ribbon (or plate) in a body of a selected solvent, and providing relative movement between the ribbon and solvent with the direction of relative movement being generally normal to the plane of the ribbon.

Abstract: The invention is an improvement in apparatus for growing crystalline bodies from the melt. The apparatus comprises a crucible and a novel die assembly in which the die assembly is made in two parts and essentially comprises inner and outer concentric members. The inner and outer members are spaced from one another to define an annular lower capillary section. One member is longer than the other and is shaped so that its upper end overhangs and engages the upper end of the other member. A plurality of upstanding dies are formed in the upper end of the longer member. Each of the dies has a top end surface and is slotted in a generally radial direction with the slots being deep enough to intersect the annular space between the two members. The slots in the dies serve as capillaries to provide communication between the lower capillary section and the top end surfaces of the dies.

Abstract: The invention is an improved apparatus for use in a system for growing crystalline bodies from the melt. The apparatus has a novel crucible die assembly in which the dies are located in cavities in the crucible side wall.