1. The other model antiferroelectric: PbHfO3 thin films from ALD precursors.
- Author
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Hanrahan, Brendan, Milesi-Brault, Cosme, Leff, Asher, Payne, Alexis, Liu, Shi, Guennou, Mael, and Strnad, Nicholas
- Subjects
THIN films ,ATOMIC layer deposition ,LEAD titanate ,BARIUM titanate ,HYSTERESIS loop ,FERROELECTRIC thin films ,ENERGY storage ,ENERGY density - Abstract
Antiferroelectric PbHfO
3 is grown from atomic layer deposition precursors lead bis(dimethylaminomethylpropanolate) and tetrakis dimethylamino hafnium with H2 O and O3 oxidizers in thicknesses from 20 nm to 200 nm at a substrate temperature of 250 °C. X-ray analysis shows an as-grown crystalline PbO phase that diffuses into an amorphous HfO2 matrix upon annealing to form a randomly oriented, orthorhombic PbHfO3 thin film. Electrical characterization reveals characteristic double hysteresis loops with maximum polarizations of around 30 µC/cm2 and transition fields of 350 kV/cm–500 kV/cm depending on the thickness. Temperature-dependent permittivity and polarization testing show a phase transition at 185 °C, most probably to the paraelectric phase, but give no clear evidence for the intermediate phase known from bulk PbHfO3 . The energy storage density for the films reaches 16 J/cm3 at 2 MV/cm. A dielectric tunability of 221% is available within 1 V for the thinnest film. These results highlight the unique spectrum of properties available for thin film perovskite antiferroelectrics. [ABSTRACT FROM AUTHOR]- Published
- 2021
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