... Single-crystalline eutectic oxide fibres are needed to reinforce metal, intermetallic and ceramic matrices to obtain high temperature composites. ... The method of internal crystallization was developed in Laboratory of Reinforced Systems of Solid State Physics Institute initially to produce oxide-matrix/molybdenum-matrix composites, which were considered mainly as model ones. ... Figure 1 . ... The oxide/molybdenum block is then moved to a cold zone of the furnace to crystallize the fibres. ...