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Konstantin Astafiev

Related publications (14)

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Quasi-Debye microwave loss as an intrinsic limitation of microwave performance of tunable components based on SrTiO3 and BaxSr1-xTiO3 ferroelectrics

Nava Setter, Alexander Tagantsev, Konstantin Astafiev

A model of the quasi-Debye loss mechanism in SrTiO3 and Ba0.6Sr0.4TiO3 perovskite ferroelectrics at microwave frequencies is presented. The field dependence and the size of the field-induced quasi-Debye loss contribution in SrTiO3 and Ba0.6Sr0.4TiO3 system ...

2005

Strain relaxation of epitaxial SrTiO3 thin films on LaAlO3 by two-step growth technique

Nava Setter, Paul Muralt, Alexander Tagantsev, Konstantin Astafiev

Using pulsed-laser deposition, a two-step growth technique was applied to epitaxial SrTiO3 (STO) thin films on LaAlO3 substrates providing a way to obtain an effective strain relaxation in these films otherwise strained due to lattice mismatch between film ...

2005

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Structural and dielectric properties of epitaxial SrTiO3 (STO) thin films on LaAlO3 substrates fabricated by a two-step growth technique using pulsed laser deposition were investigated by in situ and ex situ observations in terms of strain relaxation from ...

2005

Ferroelectric thin films are widely studied nowadays as potential replacements for semiconductors in modern tunable microwave devices such as tunable filters, phase-shifters, frequency mixers, power dividers, etc. Recent progress in the deposition of compl ...

EPFL2004

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The behavior of dielectric loss in SrTiO3 thin films at different microwave frequencies under the dc bias voltage applied is analyzed. Two types of differently processed SrTiO3 thin films (as deposited and oxygen-annealed) deposited by the pulse laser depo ...

2004

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Properties and fabrication status of microdevices for microwaves based on polar ceramics are reviewed. We discuss bulk acoustic wave devices with AlN films, rf-MEMS capacitive switches with high permittivity materials, and tunable ferroelectrics. The relev ...

2004

Crossover between extrinsic and intrinsic dielectric loss mechanisms in SrTiO3 thin films at microwave frequencies

Nava Setter, Alexander Tagantsev, Konstantin Astafiev

The do bias field. dependence of the dielectric loss in SrTi03 thin films deposited onto MgO substrate is investigated. The experimental data obtained at different frequencies of the ac field (8 and 16 GHz) from differently processed films (as deposited an ...

2004

Shift of phase transition temperature in strontium titanate thin films

Nava Setter, Alexander Tagantsev, Konstantin Astafiev

The results of structural and electrical characterizations of SrTiO3 thin films deposited onto MgO and LaAlO3 substrates by pulsed laser deposition technique are presented. The influence of substrate and annealing procedure on the crystalline structure and ...

2003

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A review of the properties of ferroelectric materials that are relevant to microwave tunable devices is presented: we discuss the theory of dielectric response of tunable bulk materials and thin films; the experimental results from the literature and from ...

2003

Can the addition of a dielectric improve the figure of merit of a tunable material?

Nava Setter, Alexander Tagantsev, Konstantin Astafiev

The influence of addition of a low-loss linear dielectric material to a tunable ferroelectric material has been investigated in terms of the electrostatic consideration. The calculations of the dielectric loss and dielectric non-linearity of ferroelectric- ...

2003