Ultrasonically accelerated crystallization processing for the nanosize ferrite powders

초록

A new technique capable of accelerating the crystallization of ferrite powder at low temperature is developed. Effects of the ultrasonic waves on the crystallization were studied for ferrite powders prepared using the co-precipitation method. The crystallization of the ferrite powders exposed ultrasonic waves was characterized by the XRD. The amorphous ferrite powders prepared using the co-precipitation method were crystallized as a result of the exposure to the ultrasonic waves for 5h and the crystallization of the ferrite powders became more enhanced in proportion to the time exposed. The ferrite powder exposed to the ultrasonic waves for 25h had higher crystallinity and a large specific surface area than the ferrite powder calcined at 500℃ for 2h. Through the ultrasonically accelerated crystallization processing, the ferrite nano powders were obtained at room temperature without a high temperature treatment of the powders-the calcining process. This ultrasonically accelerated crystallization processing is a new process for the nano-size ferrites powder processing.