Electrical Properties of Ferroelectric Thin Films Crystallized by Microwave Heating

Epitaxial Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films on the Nb-doped SrTiO₃ (Nb:STO) substrate were obtained by the method that is combined with a sol-gel method and microwave heating. Amorphous PZT thin films were coated on the Nb-doped Nb:STO substrate by a sol-gel method and then crystallized by microwave heating. The effects of microwave heating on the microstructure and ferroelectric properties of the PZT films were investigated through a comparative study with conventional heating. By microwave heating, the crystallized PZT films epitaxially grow on the Nb:STO substrate and present a symmetric P-E hysteresis loop. The effective charge density calculated from leakage current for the PZT films crystallized by microwave heating is a magnitude smaller than that for those crystallized by conventional heating. Therefore, the microwave heating can affect the P-E hysteresis loops by reducing the space charges at the PZT/Nb:STO interface during the crystallization. The results demonstrate that microwave heating can not only reduce the crystallization temperature and time, but also improve the ferroelectric properties of PZT films.