Improvement of nucleation and electrical properties of Bi3.15Nd0.85Ti2.99Mn0.01O12 thin films with an upper Bi4Ti3O12 buffer layer

Abstract

A highly (117)-preferred Bi3.15Nd0.85Ti2.99Mn0.01O12 (BNTM) thin film with an upper Bi4Ti3O12 (BTO) buffer layer was fabricated on Pt(111)/Ti/SiO2/Si(100) substrates by a sol–gel method. The effects of the added upper Bi4Ti3O12 (BTO) layer on the structural and electrical properties of BNTM were investigated. X-ray diffraction, SEM and AFM images indicated that BTO/BNTM thin films exhibited a significantly higher (117) orientation and larger grain growth compared with the BNTM thin films (without the upper BTO layer). It was found that the BTO/BNTM thin films further showed the relatively larger remanent polarization (2P r = 94.3 μC/cm2) and dielectric constant (e r = 467.8). The enhancement of piezoelectric properties was also obtained in BTO/BNTM thin films. Moreover, the BTO/BNTM thin films displayed the better fatigue properties, degraded by only 7.4 % after 109 pulse cycles as compared to 30.2 % for BNTM thin films. A highly (117)-preferred Bi3.15Nd0.85Ti2.99Mn0.01O12 (BNTM) thin film with an upper Bi4Ti3O12 (BTO) buffer layer was fabricated on Pt(111)/Ti/SiO2/Si(100) substrates by a sol–gel method. The effects of the added upper Bi4Ti3O12 (BTO) layer on the structural and electrical properties of BNTM were investigated. X-ray diffraction, SEM and AFM images indicated that BTO/BNTM thin films exhibited a significantly higher (117) orientation and larger grain growth compared with the BNTM thin films (without the upper BTO layer). It was found that BTO/BNTM thin films further showed the relatively larger remanent polarization (2P r = 94.3 μC/cm2) and dielectric constant (e r = 467.8). The enhancement of piezoelectric properties was also obtained in BTO/BNTM thin films. Moreover, the BTO/BNTM thin films displayed the better fatigue properties, degraded by only 7.4 % after 109 pulse cycles as compared to 30.2 % for BNTM thin films.