a single crystal pull apparatus has a multilayer crucible wherein the crucible has an outer crucible , an insertable layer intimately fitted thereon , and a wire frame positioned between the insertable layer and an inner crucible . the insertable layer , wire frame and inner crucible are preferably composed of platinum . furthermore the insertable layers have thin walls and the frame has a small diameter such that they can be easily reshaped after any deformation occurring as a result of the single crystal growth process .