Ferroelectric and dielectric multilayer heterostructures based on KTa0.65Nb0.35O3 and Bi1.5-xZn0.92-yNb1.5O6.92–1.5x-y grown by pulsed laser deposition and chemical solution deposition for high frequency tunable devices

Abstract Epitaxial growth of Bi 1.5–x Zn 0.92–y Nb 1.5 O 6.92–1.5x–y (BZN) thin films was achieved on (100) pc LaAlO 3 substrate by pulsed laser deposition (PLD) and by chemical solution deposition based on Pechini process. Effect of bismuth and zinc deficiency on the BZN thin films obtained by PLD was discussed, in relation with the starting target composition. Dielectric permittivity and bandgap values were determined from electrical and spectroscopic ellipsometry measurements performed on randomly oriented films grown on Pt/Si substrate. BZN thin films obtained by PLD exhibit, at 100 kHz, a dielectric constant of e r  = 203 and quite low dielectric losses of tanδ = 5 × 10 − 2 . Epitaxial ferroelectric − dielectric KTa 0.65 Nb 0.35 O 3 (KTN) − Bi 1.5–x Zn 0.92–y Nb 1.5 O 6.92–1.5x–y (KTN on BZN and BZN on KTN) bilayers were obtained by PLD on (100) pc LaAlO 3 with the insertion of a suitable buffer layer of KNbO 3 in the case of KTN on BZN. Such multilayer heterostructures with an epitaxial growth control of each layer are promising candidates for potential integration in microwave devices.