Pyroelectric PZT/PMNZTU composite thick films

Uranium doped lead magnesium niobate–lead zirconate titanate (PMNZTU) composite thick films have been fabricated on silicon substrates using a composite sol–gel technique. A slurry, made up of PMNZTU powder and PZT sol, was spun onto a silicon substrate and fired to yield a porous skeletal ceramic structure. Subsequent sol infiltration and pyrolysis was used to modify the density of the films prior to final sintering at 710 °C.Pyroelectric and dielectric properties have been measured as a function of sol infiltration. The pyroelectric coefficients (pmax = 2.74 C m−2 K−1) of the composite thick films were found to be comparable to tape cast and monolithic ceramics of similar composition (2.8 and 3.0 C m−2 K−1, respectively).Maximum figures-of-merit (FOM) (FV = 3.45 × 10−2 m2 C−1, FD = 1.01 × 10−5 Pa−1/2), calculated using the electrical properties of the thick films, can be compared with those of screen printed thick films (FV = 2.7–3.9 × 10−2 m2 C−1, FD = 0.8–1.1 × 10−5 Pa−1/2) processed at temperatures of approximately 1100 °C. The ability to directly integrate thick pyroelectric films onto substrates at temperatures as low as 710 °C, while maintaining competitive figures-of-merit is of considerable interest for future device applications.