Interfacial structure and ferroelectric properties of PZT/SrRuO3 heterostructures on MISCUT (001)SrTiO3

A heterostructure of (001)PZT(53/47)/(110)SrRuO3(SRO) was deposited on a mi scut (001)SrTiO3(ST) substrate by a magnetron sputtering. The film thicknes s of the PZT and SRO ranged from 100nm to 200nm. The miscut angles were typ ically 1.7 degrees. The heterostructure was grown on the miscut ST substrat es under a step-flow growth. The heterostructure was tightly bonded to the ST substrate without an interfacial layer. The sputtered PZT thin films wer e tetragonally deformed with c=4.16 Angstrom (bulk c-lattice parameter, 4.1 4 Angstrom). A room temperature dielectric constant of the PZT thin films w as 200 to 300 at 1 kHz. The P/E hysteresis measurements indicated that the saturation polarization P-s was 40 mu C/cm(2) with a coercive field E-c of 400 kV/cm to 500 kV/cm. The E-c observed was one order of magnitude higher than a bulk value for PZT The high values of E-c were observed in a perfect c-domain orientation without an interfacial layer or 90 degrees domains.