La-doped effect on the ferroelectric properties of Bi4Ti3O12–SrBi4Ti4O15 thin film fabricated by pulsed laser deposition

Abstract

Bi 4 Ti 3 O 12 – SrBi 4 Ti 4 O 15 (BT–SBTi) thin film was fabricated successfully on Pt/TiO2/SiO2/Si(110) substrates by the pulsed laser deposition technique. Films annealed at 650 °C by the rapid temperature process (RTP) have Pr=12 μC/cm2. But, the fatigue behavior has been observed although no obvious decrease in Pr up to 105 s retained time in the BT–SBTi capacitor. After being La doped, the Bi3.25La0.75Ti3O12–SrBi4Ti4O15 (BLT–SBTi) has fatigue free properties. Pr=13.5 μC/cm2 was measured in a BLT–SBTi film of 300 nm thickness. It did not show any significant fatigue up to 1010 switching cycles above the applied field of 250 kV/cm. It also has good retention properties. The field dependence of fatigue behavior and La-doped effect are discussed.

Effect of Oxygen Mixing Percentage on Mechanical and Microwave Dielectric Properties of SrBi4Ti4O15 Thin Films

“…Figure 1 displays the XRD patterns of SrBi 4 Ti 4 O 15 thin films that were formed at different OMPs and annealed in a microwave furnace at 550°C for around 20 min. From XRD patterns, it is clear that all the thin films are exhibited a polycrystalline nature with orthorhombic structure without any secondary phases and peaks in X-ray pattern resemble the typical JCPDS file (43-0973) and other reported literature [9,15]. The peak broadening indicates that thin films are grown in a nanocrystalline nature due to variations of processing parameters.…”

“…On the other hand, it was reported that SrBi 4 Ti 4 O 15 thin films were extensively studied, and various techniques have been employed to study their structural, morphological, dielectric properties at low frequency, ferroelectric, piezoelectric properties, etc. [9][10][11]. However, there are not many studies that specifically addressed the microwave dielectric characteristics.…”

Substitution site of La ions in La-doped Bi4Ti3O12–SrBi4Ti4O15 intergrowth ferroelectrics

“…The remnant of La-doped BTO-SBTi is enlarged by nearly 60% in comparison with the 2P r at zero doping [16], and the fatigue-endurance property is improved as well [6]. With the aim of understanding ferroelectric properties from the structural point of view, the La ions concentration in each unit of the intergrowth has been estimated with the aid of the Curie temperature dependences on La content [16].…”

“…To meet industrial requirements, a great deal of research has been carried out to improve the ferroelectric and fatigue-endurance properties. Doping, constructing intergrowth structure purposely, and synthesizing solid solution are all helpful methods [6]. Substituting more stable lanthanum for volatile Bi in BTO or SBTi can improve their ferroelectric properties.…”