High dielectric tunability with high thermal stability of the (111) highly oriented 0.85Pb(Mg1/3Nb2/3)-0.15PbTiO3 thin film prepared by a sol-gel method

• Published in: Journal of the European Ceramic Society 2021-10, Vol.41 (13), p.6482-6489
• Main Authors: Han, Feifei, Hu, Yuhao, Peng, Biaolin, Liu, Laijun, Yang, Rusen, Ren, Kailiang
• Format: Article
• Language: English
• Subjects: Dielectric tunability; Highly oriented; PNRs; Sol-gel; Thin film
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2021.06.034

Ferroelectric thin films with high tunability, low dielectric loss, high figure-of-merit (FOM) and high thermal stability are attractive to military and civil tunable devices such as phase shifters, filters, etc. In this work, the (100), (110) and (111) highly oriented 0.85Pb(Mg1/3Nb2/3)-0.15PbTiO3 (PMN-15PT) relaxor ferroelectric thin films were prepared by a sol-gel method. The (111) highly oriented PMN-15PT thin film has high dielectric tunability (η) value of ∼ 80% at 1500 kV/cm, high thermal stability (±2% variation) from room temperature to ∼ 450 K and the dielectric tunability is independent from 500 Hz to 10 kHz. The high dielectric tunability of the (111) highly oriented PMN-15PT thin film is associated to the reorientation of polar nanoregions (PNRs) and intrinsic lattice phonon polarization. Meanwhile, the excellent thermal stability may be attributed to the large dielectric diffuseness degree (γ ∼ 1.81) derived from the modified Curie-Weiss law. It is believed that the (111) highly oriented PMN-15PT thin film is an attractive material in the application of the next-generation tunable devices.