Enhancement of breakdown strength of SrTiO3/nano-SiO2 composite film prepared by sol-gel technology

Abstract

Dielectric (1-x)SrTiO 3 /xSiO 2 (x=0, 0.01, 0.05 and 0.1) composite thin films were deposited onto Pt (100)/Ti/SiO 2 /Si substrates via sol-gel and spin coating technology and their surface morphology was examined by field emission scanning electron microscopy, indicating that surface morphology was apparently influenced by the nano-SiO 2 addition. A broad adsorption band at 3200-3500 cm-1 attributed to stretching vibrations of O-H bonds in the absorbed water was observed in fourier transform infrared spectroscopy (FTIR). The X-ray photoelectron spectroscopy (XPS) results show that nano-SiO 2 particles facilitate water absorption of STO thin films. The breakdown strength of SrTiO 3 /nano-SiO 2 composite films is increased to about 332 MV/m. At the same time, the leakage current of 0.9SrTiO 3 /0.1SiO 2 composite thin films decreases by two orders of magnitude under high electric field. Above results show that nano-SiO 2 particles facilitate water absorption of the thin films, making SrTiO 3 act as an effective solid state electrolyte for the anodic oxidation to achieve higher breakdown strength.

Temperature dependence of charge screening in Fe/SrTiO 3 heterostructure

“…Curves of the polarization-voltage (P -V ) and the leakage current-voltage (I-V ) of the Fe/STO heterostructure are shown in fig. 2(b), similar to those of other STO films[17,20,21]. Under an applied voltage of 5 V the maximum leakage current and polarization are 0.49 × 10 −8 A/cm 2 and 0.051 μC/cm 2 , respectively.…”