Growth and properties of PZT -based perovskite multilayers for sensor applications

We have studied ferroelectric properties of Pb (Zr 0.6 Ti 0.4 )O 3 (PZT)/SrTiO 3 thin films grown on platinized silicon substrates using pulsed-laser deposition and magnetron sputtering technique. The spontaneous polarization (P s ) and remnant polarization (P r ) varies between 15.5 K and 100 K from 33-38 μC/cm 2 and 25-30 μC/cm 2 , respectively. Similar values of P s and P r were also observed until temperature reached to 300K. However, more pronounced ferroelectric hysteresis loops were observed between T= 323 to 353 K. The P s and P r remain around 36-40 μC/cm 2 and 23-28 μC/cm 2 , respectively, between T = 323 to 353 K. The remnant polarization remains fairly consistent over the chosen temperature range. X-ray diffraction and high-resolution microscopic studies reveal that the Pb (Zr 0.6 Ti 0.4 ) 0 3 layers are superior in crystalline quality than that of SrTi0 3 . The PZT in multilayered films show remarkably enhanced polarization properties relative to their single layers on the same substrates. The collective contribution of dipole moments from each layer is the reason for such enhancement in polarization properties. This growth strategy may be very useful for fabrication of sensitive sensing and other relevant devices.