Chemical interactions between strontium-doped praseodymium manganite and 3mol% yttria-zirconia

The interfacial reaction between(Pr0.8Sr0.2)(y)MnO3 (PSM, y = 0.9, 1.0, 1.0 5) film and 3 mol% yttria tetragonal zirconia (TZ3Y) substrate has been stu died at 1200 and 1400 degrees C in air. A diffusion layer of Pr and Mn in z irconia, which was identified to be a cubic phase of zirconia, was detected in all specimens. When the solubility limit of Pr ions in the cubic zircon ia was reached; a pyrochlore phase, Pr2Zr2O7, was formed. A-delay for the f ormation of pyrochlore phase was observed for the A-site sub-stoichiometric and stoichiometric PSM at 1200 degrees C. For the A-site over-stoichiometr ic PSM, a Pr-rich (Pr,Zr)O-x phase was detected at the interface besides th e pyrochlore phase; At 1400 degrees C, a relatively thick layer of pyrochlo re phase was formed after 24 hour heat treatment in all specimens. The amou nt of the pyrochlore phase formed at the interface depends on the A-site st oichiometry of perovskite in the initial stage. The growth of the pyrochlor e layer after, the initial stage, however, appears to be determined by cont act area between PSM and the substrate.