Film structure and ferroelectric properties of vanadium-doped Sr 0.8Bi 2.3Ta 2O 9 thin films

Abstract

Vanadium-doped strontium bismuth tantalate Sr 0.8Bi 2.3(Ta 2-xV x)O 9 (SBTV) (x=0-0.8) have been prepared on Pt/Ti/SiO 2/Si substrates using a metalorganic decomposition method. Well-crystallized and dense SBTV films can be obtained at an annealing temperature as lower as 650-700°C that can be attributed to the enhanced densification due to the addition of vanadium. With partial substitution of tantalum by vanadium up to x=0.15, a larger remanent polarization (2P r) of 30.5 μC/cm 2 can be obtained for the Sr 0.8Bi 2.3Ta 1.85V 0.15O 9 film at 800°C that is attributed to the larger grain size and increased "rattling space." Furthermore, the vanadium substitution for tantalum ion can effectively reduce the leakage current density as lower as 5×10 -8A/cm 2 at an applied electric field of 100 kV/cm because of the reduced mobility of charge carriers. However, the incorporation of vanadium does not cause appreciable negative effect on the fatigue endurance of Sr-deficient Sr 0.8Bi 2.3Ta 2O 9 films until more than 20 mol% (x=0.2) vanadium was added. © 2002 American Institute of Physics.