The objective of this SBIR Phase I program is to test the application of the Edge-defined, Film-fed, Growth process (EFG) to growth of refractory oxide eutectic fibers. Work is directed to producing a range of microstructures in the grown fibers by variation of growth process parameters. These results may be expected to indicate directions for process and fiber property optimization. The eutectic fiber produced by this technique will find application in both ceramic-and metal-matrix composite structures for high-temperature service.