Influence of Deposition Parameters and Substrate on the Quality of Pulsed‐Laser‐Deposited Pb1‐xCaxTiO3 Ferroelectric Films

Abstract

Pb 1−x Ca x TiO 3 (PCaT) thin films have been prepared by pulsed laser deposition (PLD) on Pt/TiO 2 /SiO 2 /(100)Si, (100)MgO, and Pt/(100)MgO substrates. A Pb deficiency with regard to the target composition occurs in films prepared on heated substrates, while the Ca concentration in the film remains congruent with the target composition. The onset temperature for the Pb loss changes from 250°C using nonsintered targets to 450°C if sintered targets are used; moreover, the sintered targets also produce a low particle density on the film surface (0.4 µm −2 ). Increasing the laser fluence to about 10 J/cm 2 improves the crystalline quality of the films. PCaT (x = 0.24) films obtained by PLD on Si-based substrates have a lattice tetragonality c/a = 1.014, lower than the value obtained in films prepared by other methods. The film tetragonality can be slightly increased to c/a = 1.022 by using MgO substrates and much more efficiently by reducing the Ca concentration, up to reach c/a = 1.048 in Ca free films. The increase of the film tetragonality induces an enhancement of the film orientation with the [001] axis perpendicular to the substrate surface; moreover, the typical values of the spontaneous and remanent polarizations increase up to P r ≈ 34 µCؒcm −2 .

Synthesis of Dense Lead Titanate Ceramics with Submicrometer Grains by Spark Plasma Sintering

“…The contribution of ohmic losses was negligible because of the high resistance of the samples, ϳ1 G⍀. 19 The typical remanent polarization values, estimated from the hysteresis loops, were 1.2 and 0.74 C⅐cm Ϫ2 , the spontaneous polarization values were 2.8 and 2.0 C⅐cm Ϫ2 , and the coercive fields were 8.9 and 2.7 kV⅐cm Ϫ1 , for the SPS and CS pellets, respectively. The measured spontaneous polarization values were in agreement with that (2 C⅐cm Ϫ2 ) reported for well-sintered PbTiO 3 ceramics containing small amounts of dopants as sintering aids.…”

METALLO-ORGANIC DECOMPOSITION SYNTHESIS AND CHARACTERIZATION OF FERROELECTRIC (PB1 −XCAX)TIO3 Thin Films

“…In the past, PCT films have been deposited by rf-magnetron sputtering [8], a multiple-cathode RF-magnetron sputtering [9], pulsed laser deposition [10] and sol-gel technique [11][12][13][14][15][16]. Due to high degree of composition control, lower processing temperature and better large area homogeneity coating, the sol-gel chemical processing of PCT film is widely investigated.…”

Ca Substituted PbTiO3 Thin Films for Infrared Detectors

“…2. AFM is characterized by slight surface roughness with a uniform crack free microstructure The surface roughness obtained from AFM software routine was found to be 3.65 nm which is lower than that obtained by Martin et al [9] for films produced by laser ablation technique. envelope of the photon bands of a metal-oxygen-metal bond of a solid network.…”