Pulsed laser deposited KNbO$_3$ thin films for applications in high frequency range

A. Rousseau (1) , Vincent Laur (2) , Maryline Guilloux-Viry (1) , Gérard Tanné (2) , Fabrice Huret (2) , S. Députier (1) , A. Perrin (1) , F. Lalu (3) , Paul Laurent (2)

1 LCSIM - Laboratoire de Chimie du solide et inorganique moléculaire
2 LEST - Laboratoire d'Electronique et Systèmes de Télécommunications
3 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse

Potassium niobate thin films were grown by pulsed laser deposition on various substrates. Influence of deposition conditions on film characteristics was studied. Structural investigation evidenced that single phase polycrystalline randomly oriented films were grown on sintered alumina whereas epitaxial films were grown on (100)SrTiO$_3$ and (100)MgO substrates. The microstructure was highly controlled by the structural characteristics. Interdigited capacitors built from KNbO3 films on two different substrates (alumina and MgO) showed the strong influence of the structural characteristics on the dielectric behavior. The variation of the equivalent capacitance measured on the interdigital capacitor on MgO was 6.4% at 2.5 GHz while it was 1.5% on alumina, in both cases for a moderate applied field of $\sim$15 kV cm$^{-1}$. The results show the potentiality of these ferroelectric materials for use in frequency agile microwave electronics.

Mots clés: Ferroelectric properties; Structural properties; Pulse laser deposition; Potassium niobate

Domaines: Autre [cond-mat.other]

A. Rousseau, Vincent Laur, Maryline Guilloux-Viry, Gérard Tanné, Fabrice Huret, et al.. Pulsed laser deposited KNbO$_3$ thin films for applications in high frequency range. Thin Solid Films, 2006, 515, pp.2353-2360. ⟨10.1016/j.tsf.2006.04.010⟩. ⟨in2p3-00128650⟩