Flower-like Pb(Zr0.52Ti0.48)O3 nanoparticles on the CoFe2O4 seeds

We grew an epitaxial Pb(Zr0.52Ti0.48)O3 (PZT) buffer layer on the SrTiO3 (STO) substrate with a pulsed-laser deposition (PLD) system, and then deposited the composite thin film of CoFe2O4 (CFO) and PZT phases. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM) showed that the two only PZT and CFO phases in the film had perfect epitaxial structures. The strain arose around the CFO particles because of the lattice mismatch between the two phases, leading to high elastic energy at the interface between CFO and PZT. As a result, part of the CFO particles served as seeds. When another PZT layer was deposited, the elements of PZT congregated on the CFO seeds to decrease the elastic energy, forming the flower-like nanostructures on the CFO seeds, which were observed by scanning electron micrography (SEM) and TEM. The reason for the flower-like nanostructures forming was discussed.