Film structure and ferroelectric properties of vanadium-doped Sr0.8Bi2.3Ta2O9 thin films

Abstract

Vanadium-doped strontium bismuth tantalate Sr0.8Bi2.3(Ta2-xVx)O-9 (SBTV) (x = 0-0.8) have been prepared on Pt/Ti/SiO2/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 degreesC 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 muC/cm(2) can be obtained for the Sr0.8Bi2.3Ta1.85V0.15O9 film at 800 degreesC 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 x 10(-8) A/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 Sr0.8Bi2.3Ta2O9 films until more than 20 mol % (x = 0.2) vanadium was added. (C) 2002 American Institute of Physics.