A novel "one-pot" synthetic method has been reported for the preparation of (NiFe 2O 4) x-(BaFe 12O 19) 1-x composites. The synthesized composites were characterized using thermogravimetric analysis, differential scanning calorimetric analysis, X-ray diffraction, dynamic light scattering technique, scanning electron microscopy, and vibrating sample magnetometer. The (NiFe 2O 4) x-(BaFe 12O 19) 1-x composites prepared by this method showed crystallographically two phase behavior, but magnetically a good single phase exchange spring-coupled behavior with high saturation magnetization as well as high coercivity. © 2011 The American Ceramic Society.