Field emission scanning electron microscope (FE-SEM) (Hitachi, Japan) and transmission electron microscope (TEM) (HR-TEM, Model Tecnai—Philips F30, FEI Co., Hillsboro) was used to observe the particle morphology and size of the powders. The elemental composition of the powders was analyzed using energy dispersive X-ray (EDX) (Bruker axes) attached to the field emission scanning electron microscope (FE-SEM) (Hitachi-S-4800, Tokyo, Japan).