Dielectric and Tunability Properties of Nanostructured Nd-modified Pb(Zr_xTi_1-x)O₃ Thin Films up to Microwave Frequencies

Abstract

Dielectric properties of nanocrystalline Nd-modified Pb(Zr_xTi_1-x)O₃ thin films were studied in frequency range f = 100 Hz –20 GHz. Thin films were prepared by pulsed laser deposition on MgO(100) substrates. Inter-digital electrodes and coplanar waveguide transmission line technique were used for dielectric characterization. In the dielectric function ɛ_r(f, T), two interesting anomalies were found at low frequencies. Diffusive phase transition had relaxor-type behaviour, and an extra dielectric relaxation maxima were found below Curie temperature T_C. At higher frequencies above 5 GHz, relative permittivity ɛ_r(f) response was flat up to 20 GHz, and high maximum tunability n_r,max = 19% was achieved.

Keywords:

• PNZT thin films
• nanocrystalline
• dielectric relaxation
• coplanar wave- guide
• micro-wave frequency

Acknowledgments

Finnish Foundation for Technology Promotion, Riitta and Jorma J. Takanen Foundation, Tauno Tönning Foundation, and Microcopy and Nanotechnology Center (MNT) of University of Oulu are acknowledged.