Fabrication and optical properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 thin films on Si substrates using the PLD method

Epitaxial 0.67Pb(Mg
_1/3
Nb
_2/3
)O
₃
-0.33PbTiO
₃
(PMN-PT) thin films with electro-optic effects were fabricated on (La
_0.5
Sr
_0.5
)CoO
₃
(LSCO)/CeO
₂
/YSZ-buffered Si(001) substrates using double-pulse excitation pulsed laser deposition (PLD) method with a mask placed between the target and the substrate. Epitaxial growth of PMN-PT thin films was undertaken using the two-step growth method of PMN-PT film. The PMN-PT seed layer was deposited at 500degC on the LSCO/CeO
₂
/YSZ/Si, which temperature was the same as that used for LSCO deposition. The PMN-PT thin films were deposited on the PMN-PT seed layer at 600degC, which enables growth of high-crystallinity PMN-PT films with smooth surfaces. We obtained optimum fabrication conditions of PMN-PT film with micrometer-order thickness. Resultant films showed high crystallinity with full width at half maximum (FWHM)=0.73 deg and 1.6 mum thickness. Electro-optic properties and the refractive index value were measured at 633 nm wavelength using the prism coupling method. The obtained refractive index was 2.59. The electro-optic coefficients r
₁₃
and r
₃₃
were determined by applying the electrical field between a semitransparent, thin top electrode of Pt and a bottom LSCO electrode. The electro-optic coefficient was r
₁₃
=17 pm/V at transverse electric field (TE) mode and r
₃₃
=55 pm/V at transverse magnetic field (TM) mode.