Influence of Pb and La contents on the lattice configuration of La-substituted Pb(Zr,Ti)O3 films fabricated by CSD method

The influence of Pb and La contents on the lattice configuration in La-substituted Pb(Zr
_0.65
,Ti
_0.35
)O
₃
(La-PZT) films was systematically investigated. La-PZT films with various La and Pb contents were fabricated on Pt/Ti/SiO
₂
/Si substrates by chemical solution deposition (CSD). In the La-PZT films with a Pb content ratio of 125% relative to a stoichiometric value, La ions were substituted for not only A-site ions but also B-site ions at La contents greater than 3 mol%. La substitution for B-site seems to cause larger reduction of the unit cell size. In addition, we found that in the La-PZT films with a La content of 3 mol%, the Pb content of 116 mol% (120% relative to a stoichiometric value) was optimum from the viewpoint of site occupancy. This indicates that excess Pb prevented the A-site substitution of La ions.