Formation and characteristics of highly c-axis-oriented Bi3.25La0.75Ti3O12 thin films on SiO2/Si(100) and Pt/Ti/SiO2/Si(100) substrates

Abstract

Highly c-axis-oriented Bi3.25La0.75Ti3O12 (BLT) films with a homogeneous in-plane orientation were successfully grown on SiO2/Si(100) and Pt/Ti/SiO2/Si(100) substrates by a sol-coating route. The substitution of lanthanum ions for bismuth ions in the layered perovskite suppressed the formation of pyrochlore phase and enhanced the c-axis-oriented growth. The c-axis-oriented BLT film fabricated on a Pt/Ti/SiO2/Si(100) substrate showed fatigue-free characteristics with a large remanent polarization of 26–28 μC/cm2 and the coercive field of 50–75 kV/cm. These features significantly enhance the potential value of the BLT film for the applications to high-density ferroelectric random-access memories devices. In addition, the c-axis-oriented BLT film, with a homogeneous in-plane orientation on an amorphous surface, can be used as a suitable template material for applications to various electro-magneto-optic devices.