| 1. |
- Abadei, Saeed, 1961, et al.
(author)
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Low frequency characterisation of laser ablation deposited thin Na0.5K0.5NbO3 (NKN) films for microwave application
- 2001
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In: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 263:1, s. 173-179
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Journal article (peer-reviewed)abstract
- Experimental results on three types of Na0.5K0.5NbO3 (NKN) film capacitor structures are presented. The epitaxial NKN thin films have been deposited on (100) Si (high resistivity), SiO2/Si (low resistivity) and Pt/Si (low resistivity) substrates using laser ablation deposition. Both straight slot and interdigital electrode have been deposited on top of the NKN films. The leakage current and low frequency dielectric properties (I-V, C-V, tanδ-V) of the structures have been measured at 1 MHz as a function of electric field at room temperature. In all three types of capacitor structures the leakage currents in a-b plane are very small, while along c-axis there are extremely large leakage currents. On low resistivity silicon substrates the tunability of the dielectric permittivity is about 12% and loss tangent is low also. On high resistivity (ρ>10 kOhm cm) silicon substrate the tunability at 1 MHz is extremely high, about 10 times, and the losses are also high. On the other hand at microwave frequencies the losses are small (tanδ
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| 2. |
- Gevorgian, Spartak, 1948, et al.
(author)
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Strain induced ferroelectrosity in epitaxial SrTiO3 films
- 2001
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In: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 33:1-4, s. 311-321
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Journal article (peer-reviewed)abstract
- Microwave performances of planar capacitors formed on epitaxial SrTiO 3 (STO) films reveal that two-dimensional, in-plane strain in the film lead to a formation of a stable non-cubic, low symmetry ferroelectric phase. The residual polarization vector has two stable states, normal to the film surface, and may be switched under applied DC bias. Due to the charges in surface/interface levels, the films may contain either a single or opposing domains
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