Photoactivation of Sol–Gel Precursors for the Low-Temperature Preparation of PbTiO3 Ferroelectric Thin Films

Authors


  • J. Nino—contributing editor

  • This work was financially supported by the Spanish Project MAT2007-61409.

†Author to whom correspondence should be addressed. e-mail: nekane.martin@hotmail.com

Abstract

PbTiO3 thin films have been prepared by ultraviolet (UV)-assisted rapid thermal processing (RTP) (photochemical solution deposition) following a sol–gel method. To prepare photo-sensitive sols, two types of photo-initiators compounds, N-methyldiethanolamine and propylenaldehyde, have been incorporated into the system. The effect of the type and amount of photo-initiator on the UV light absorption of the respective precursor solutions was studied. At 400°C, the PbTiO3 perovskite phase was observed by X-ray diffraction in the films. These films show an improved ferroelectric response when they are UV-irradiated during the annealing as compared with those nonirradiated. Moreover, properties are significantly better in PbTiO3 thin films prepared by using N-methyldiethanolamine as a photoinitiator. Thus, films prepared from sols containing N-methyldiethanolamine, UV-irradiated and crystallized by RTP at 400°C, show well-defined ferroelectric hysteresis loops with values of remnant polarization and coercive field of Pr∼11.9 μC/cm2 and Ec∼235 kV/cm, respectively.

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