Growth and characterization of Pb(Mg1/3Nb2/3)O3 and Pb(Mg1/3Nb2/3)O3-PbTiO3 thin films using solid source MOCVD techniques

Abstract Epitaxial thin films of Pb(Mg 1/3 Nb 2/3 )O 3 (PMN) and Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 (PMN–PT) were deposited on (0 0 1) SrTiO 3 and SrRuO 3 /SrTiO 3 single crystal substrates at 700°C by the solid-source MOCVD method, using tetramethylheptanedionate (THD) sources of Pb, Mg, Nb, and Ti. Sputtered SrRuO 3 was employed as an epitaxial bottom electrode layer so that electrical property measurements could be made. Pure PMN films were prepared using pre-mixed source material (5.5 moles of Pb(THD) 4 ,1 mole of Mg(THD) 2 and 2 moles of Nb(THD) 4 ). XRD results indicated that these films were single phase and had the pervoskite structure. Rutherford Backscattering showed that Pb/Mg/Nb/O=18%/7%/13%/62%. Films of PMN–10% PT and PMN–20% PT films were also epitaxially deposited on the same substrates. The dielectric constants for these films were in the range 1200–1500 and 600–700, respectively. A 150 nm thick PMN–20% PT film was strongly dispersive. The dielectric constant for a 150 nm thick film decreased from 700 at 1 kHz to 550 at 100 kHz. The dielectric loss factor increased from 0.15 to 0.4 with increasing frequency.