Thickness Dependence of Dielectric,Leakage, and Ferroelectric Properties of Bi6Fe2Ti3O18 Thin Films Derived by Chemical Solution Deposition

We prepared Bi₆Fe₂Ti₃O₁₈ thin films on Pt/Ti/SiO₂/Si substrates with thickness ranging from ～300 to ～900 nm by using a chemical solution deposition route and investigated the thickness effects on the microstructure, dielectric, leakage, and ferroelectric properties of Bi₆Fe₂Ti₃O₁₈ thin films. Increasing thickness improves the surface morphology, dielectric, and leakage properties of Bi₆Fe₂Ti₃O₁₈ thin films and a well‐defined ferroelectric hysteresis loops can form for the thin films with the thickness above 400 nm. Moreover, the thickness dependence of saturation polarization is insignificant, whereas the remnant polarization decreases slightly with increasing thickness and it possesses a maximal value of ～20 μC/cm² for the 500 nm‐thick thin films. The mechanisms of the thickness dependence of microstructure, dielectric, and ferroelectric properties are discussed in detail. The results will provide a guidance to optimize the ferroelectric properties in Bi₆Fe₂Ti₃O₁₈ thin films by chemical solution deposition, which is important to further explore single‐phase multiferroics in the n = 5 Aurivillius thin films.     

Microstructure and ferroelectric properties of Ta-doped Bi3.25La0.75Ti3O12/ZnO thin film capacitors

Ta-doped Bi_3.25La_0.75Ti₃O₁₂(BLTT)/ZnO films were fabricated on Pt(111)/Ti/SiO₂/Si substrates by a magnetron sputtering method. Firstly, ZnO crystal thin films were grown on the substrates by a reactive sputtering method. Then, BLTT thin films were deposited on the ZnO layers at room temperature and post-annealed at 600 °C. The micromorphology, ferroelectric and dielectric properties of BLTT/ZnO films were analyzed. The XRD analysis shows that ZnO buffer layer significantly reduces the crystallization temperature of BLTT thin film. The TEM results show that lamellar BLTT grains are grown on ZnO layer at a certain angle with few elements diffusion at the interface of ZnO phase and Bi₄Ti₃O₁₂ phase. The ferroelectric properties indicate that BLTT/ZnO films exhibit different remanent polarization and coercive fields under electric field with different directions. The novel mechanism of tailoring ferroelectric properties may open new possibilities for designing special ferroelectric devices.     

Structural and electrical properties of Na0.5Bi4.0RE0.5Ti4O15 (RE=Tm,Yb and Lu) thin films

In the current study, a series of lanthanide ions, Tm, Yb and Lu, were used for doping at the Bi-site of the Aurivillius phase Na_0.5Bi_4.5Ti₄O₁₅ (NaBTi) to investigate the structural, electrical and ferroelectric properties of the thin films. In this regard, Na_0.5Bi_4.5Ti₄O₁₅ and the rare earth metal ion-doped Na_0.5Bi_4.0RE_0.5i₄O₁₅ (RE=Tm, Yb and Lu, denoted by NaBTmTi, NaBYbTi, and NaBLuTi, respectively) thin films were deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by using a chemical solution deposition method. Formations of the Aurivillius phase orthorhombic structures for all the thin films were confirmed by X-ray diffraction and Raman spectroscopic studies. Based on the experimental results, the rare earth metal ion-doped Na_0.5Bi_4.0RE_0.5Ti₄O₁₅ thin films exhibited a low leakage current and the improved ferroelectric properties. Among the thin films, the NaBLuTi thin film exhibited a low leakage current density of 6.96×10⁻⁷ A/cm² at an applied electric field of 100 kV/cm and a large remnant polarization (2P_r) of 26.7 μC/cm² at an applied electric field of 475 kV/cm.     

The effect of Bi2O3 compensation during thermal treatment on the crystalline and electrical characteristics of bismuth titanate thin films

Bismuth titanate thin films are deposited on ITO/glass substrates by rf magnetron sputtering at room temperature using a Bi₄Ti₃O₁₂ ceramic target. The deposited Bi₄Ti₃O₁₂ films are annealed in a conventional furnace in ambient air for 10 min at temperatures ranging from 550 to 640 °C. One specimen is annealed in a crucible containing additional Bi₂O₃ compensation powder, while the other specimen is annealed in ambient air. XRD analysis shows that the crystal phases of films annealed with Bi₂O₃ powder are better than those of films annealed without Bi₂O₃ powder. Furthermore, the EDS results reveal that the bismuth weight percentage of the former is higher than that of the latter. SIMS analysis shows that the bismuth decreases near the surface of Bi₄Ti₃O₁₂ film annealed without Bi₂O₃ powder, but reveals a stable distribution throughout the film annealed with Bi₂O₃ powder. These results imply that bismuth is readily evaporated during the thermal treatment process, particularly from the region near the film surface. Finally, the dielectric and polarization properties of the thin films annealed with Bi₂O₃ powder are found to be superior to those of the films annealed in ambient air.     

Effects of Ho and Ti Doping on Structural and Electrical Properties of BiFeO3 Thin Films

Effects of Ho and Ti ions individual doping and co‐doping on the structural, electrical, and ferroelectric properties of the BiFeO₃ thin films are reported. Pure BiFeO₃, (Bi_0.9Ho_0.1)FeO₃, Bi(Fe_0.98Ti_0.02)O_3+δ, and (Bi_0.9Ho_0.1)(Fe_0.98Ti_0.02)O_3+δ thin films were prepared on Pt(111)/Ti/SiO₂/Si(100) substrates by using a chemical solution deposition method. All thin films were crystallized in distorted rhombohedral structure containing no secondary or impurity phases confirmed by using an X‐ray diffraction study. Changes in microstructural features, such as grain morphology and grain size distribution, for the doped samples were analyzed by a scanning electron microscopy. From the experimental results, a low electrical leakage (1.2 × 10^?5 A/cm² at 100 kV) and improved ferroelectric properties, such as a large remnant polarization (2P_r) of 52 μC/cm² and a low coercive field (2E_c) of 886 kV/cm, were observed for the (Bi_0.9Ho_0.1)(Fe_0.98Ti_0.02)O_3+δ thin film. Fast current relaxation and stabilization observed in the (Bi_0.9Ho_0.1)(Fe_0.98Ti_0.02)O_3+δ imply effective reduction and neutralization of charged free carriers.     

Dip-coated La2Ti2O7 as a buffer layer for growth of Bi3.25La0.75Ti3O12 films with enhanced (0 1 1) orientation

Thin-films of La₂Ti₂O₇ were obtained by dip-coating process using a precursor salt in nitric acid solution. The effects of solution concentration, withdrawal speed, post-annealing duration and temperature were investigated both on grain size and orientation of the La₂Ti₂O₇ thin layers. In addition, a target with the required stoichiometry for PVD deposition of La-substituted Bi₄Ti₃O₁₂ (BLT) was successfully sintered by spark plasma sintering (SPS) at 750 °C. Finally (0 1 1)-oriented BLT ferroelectric films have been grown by RF sputtering on (1 1 0)-oriented La₂Ti₂O₇ polycrystalline thin-film. A preferential orientation of BLT thin films has been obtained after annealing at a temperature lower than 650 °C.     

Green Up‐Conversion Photoluminescence and Dielectric Relaxation of Ho3+/Yb3+‐Codoped Bi2Ti2O7 Pyrochlore Thin Films

Ho³⁺/Yb³⁺‐codoped Bi₂Ti₂O₇ pyrochlore thin films were prepared by a chemical solution deposition method, and their visible up‐conversion (UC) photoluminescence and dielectric relaxation were studied. Ho and Yb can be doped into Bi₂Ti₂O₇ lattice and single pyrochlore phase is maintained. Intense visible UC photoluminescence can be observed under the excitation of a 980‐nm diode laser. Two UC emission bands centered at 551 nm and 665 nm in the spectra can be assigned to ⁵F₄, ⁵S₂→⁵I₈ and ⁵F₅→⁵I₈ transitions of Ho³⁺ ions, respectively. The dependence of their UC emission intensity on pumping power indicates that both the green and red emissions of the thin films are two‐photon process. In addition, a Stokes near‐infrared emission centered at 1200 nm can be detected, which is due to ⁵I₆→⁵I₈ transition of Ho³⁺ ions. The thin films prepared on indium tin oxide–coated glass substrates exhibit a relatively high dielectric constant and a low dielectric loss as well as a good bias voltage stability. The dielectric relaxation of the thin films was also analyzed based on the temperature‐ and frequency‐dependent dielectric properties. This study suggests that Ho³⁺/Yb³⁺‐codoped Bi₂Ti₂O₇ thin films are promising materials for developing multifunctional optoelectronic thin film devices.     

The Influence of the Precursor on the Formation of Bi2O3 Polymorphs in CSD‐Derived Thin Films

This work examines the synthesis and characterization of crack‐free, β‐Bi₂O₃ thin films prepared on Pt/TiO₂/SiO₂/Si or corundum substrates using the sol‐gel method. We observed that the Bi‐based precursor has a pronounced influence on the β‐Bi₂O₃ phase formation. Well‐crystallized, single β‐Bi₂O₃ thin films were obtained from Bi‐2ethylhexanoate at a temperature of 400°C. In contrast, thin films deposited from Bi‐nitrate and Bi‐acetate resulted in non‐single Bi₂O₃ phase formation. TEOS was used for the stabilization of the β‐Bi₂O₃ phase. The phase composition of the thin films was characterized by means of X‐ray diffraction (XRD), whereas the morphology and thickness of the thin films were studied using scanning electron microscopy (SEM). The β‐Bi₂O₃ films' dielectric properties were characterized utilizing microwave‐frequency measurement techniques: (1) the split‐post dielectric resonator method (15 GHz) and (2) the planar capacitor configuration (1–5 GHz). The dielectric constant and dielectric loss measured at 15 GHz were 257 and 7.5 × 10^?3, respectively.     

Structural,Electrical, and Ferroelectric Properties of Nb‐Doped Na0.5Bi4.5Ti4O15 Thin Films

Ferroelectric Na_0.5Bi_4.5Ti₄O₁₅ (NaBTi) and donor Nb‐doped Na_0.5Bi_4.5Ti_3.94Nb_0.06O₁₅ (NaBTiNb) thin films were prepared on Pt(111)/Ti/SiO₂/Si(100) substrates using a chemical solution deposition method. The doping with Nb⁵⁺‐ions leads to tremendous improvements in the ferroelectric properties of the NaBTiNb thin film. Room‐temperature ferroelectricity with a large remnant polarization (2P_r) of 64.1 μC/cm² and a low coercive field (2E_c) of 165 kV/cm at an applied electric field of 475 kV/cm was observed for the NaBTiNb thin film. The polarization fatigue study revealed that the NaBTiNb thin film exhibited good fatigue endurance compared with the NaBTi thin film. Furthermore, the NaBTiNb thin film showed a low leakage current density, which was 1.48 × 10^?6 A/cm² at an applied electric field of 100 kV/cm.     

Dielectric,ferroelectric, and photoluminescent properties of Sm-doped Bi4Ti3O12 thin films synthesized by sol-gel method

We report on the structure, dielectric, ferroelectric, and photoluminescent properties of Sm³⁺-doped Bi₄Ti₃O₁₂ thin films which were prepared on fused silica and Pt/Ti/SiO₂/Si substrates by sol-gel method. The X-ray diffraction analysis confirmed that the Bi_4-xSm_xTi₃O₁₂ (BSmT) thin films were well crystallized in layered perovskite structure without any secondary phase. Raman spectra indicated that the structure of BSmT thin films was significantly distorted because of the Sm³⁺ doping. An appropriate doping amount of Sm³⁺ ions leads to obvious enhancement in ferroelectric and dielectric properties of BSmT thin films due to structure distortion and reduction in defects. In addition, the BSmT thin films also show orange-red color emission at 601?nm and long florescence lifetime (> 0.6?ms). This study indicated that lead-free BSmT thin films, which are featuring good electrical and photoluminescent properties, may have potential applications in integrated optoelectronic devices.     

Construction of multi-domain coexistence enhanced piezoelectric properties of Bi0.5Na0.5TiO3-based thin films

Although the multi-phase coexistence makes Bi_0.5Na_0.5TiO₃-based piezoelectric thin films possess stronger piezoelectric properties and more spacious application prospects in electronic devices, the domain reversal mechanism of Bi_0.5Na_0.5TiO₃-based thin films cannot be accurately understood due to the size effect. In this study, the relationship between domain structure and piezoelectric properties of the (0.94-x)Bi_0.5Na_0.5TiO₃-0.06BaTiO₃-xBi(Fe_0.95Mn_0.03Ti_0.02)O₃ thin films are studied by using visualization technology PFM, structure and electrical properties characterizations. The results show that the addition of Bi(Fe_0.95Mn_0.03Ti_0.02)O₃ creates a long-range ordered/short-range disordered nanodomain coexisting structure. This kind of coexisting domain structure can realize the long-range reversal driven by disordered nanodomains under the external electric field, reduce the potential barrier and the hysteresis, and significantly enhance the piezoelectric properties of the thin films. Under the same conditions, the piezoelectric properties of the 0.94Bi_0.5Na_0.5TiO₃-0.06BaTiO₃ thin films are enhanced nearly 2.3 times. This provides a reference for exploring the physical mechanism of high performance lead-free piezoelectric thin films.     

Fabrication and characterization of intergrown Bi4Ti3O12-based thin films using a metal-organic precursor solution

Ferroelectric intergrowth-structured Bi₄Ti₃O₁₂-based thin films have been fabricated by chemical solution deposition. Bi₄Ti₃O₁₂–SrBi₄Ti₄O₁₅ (BiT–SBTi) and SrBi₂Nb₂O₉–Bi₄Ti₃O₁₂ (SBN–BiT) precursor films crystallized in the desired intergrown BiT–SBTi and SBN–BiT structures on Pt/TiO_x/SiO₂/Si substrates by optimizing the processing conditions. Synthesized BiT–SBTi and SBN–BiT thin films exhibited ferroelectric P–E hysteresis loops. The BiT–SBTi thin films crystallized at 750 °C showed a 2P_r value approximately 20 μC/cm². Although a little smaller P_r value was observed for the SBN–BiT thin films, the squareness of a P–E hysteresis loop was superior to that of BiT–SBTi thin films. Also, the SBN–BiT thin films had a smoother surface morphology compared with BiT–SBTi thin films.     

Structural,dielectric and piezoelectric properties of (Bi0.5Na0.5)TiO3–(Bi0.5K0.5)TiO3–Bi(Zn0.5Ti0.5)O3 thin films prepared by sol–gel method

Lead free (1−x)(0.8Bi_0.5Na_0.5Ti_0.5O₃–0.2Bi_0.5K_0.5TiO₃)–xBiZn_0.5Ti_0.5O₃ (x=0–0.06) (BNT–BKT–BZT) thin films were deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by a sol–gel processing technique. The effects of BZT content on the structural, dielectric, ferroelectric and piezoelectric properties of the BNT–BKT–BZT thin films were investigated systematically. The BNT–BKT–BZT thin films undergo a transition from ferroelectric to relaxor phase with increasing temperature. The phase transition temperature decreases with the increase of BZT content. The BNT–BKT–BZT thin film with x=0.04 exhibits the best ferroelectric properties (P_max=40 µC/cm² and P_r=10 µC/cm²), largest dielectric constant (ε=560) and piezoelectric constant (d₃₃=40 pm/V). This finding demonstrates that the BNT–BKT–BZT thin film has an excellent potential for demanding high piezoelectric properties in lead free films.     

Color‐Tunable Up‐Conversion Emission and Infrared Photoluminescence and Dielectric Relaxation of Er3+/Yb3+ Co‐Doped Bi2Ti2O7 Pyrochlore Thin Films

The color‐tunable up‐conversion (UC) emission and infrared photoluminescence and dielectric relaxation of Er³⁺/Yb³⁺ co‐doped Bi₂Ti₂O₇ pyrochlore thin films prepared by a chemical solution deposition method have been investigated. The pyrochlore phase structure of Bi₂Ti₂O₇ can be stabilized by Er³⁺/Yb³⁺ co‐doping. Intense color‐tunable UC emission and infrared photoluminescence can be detected on the thin films excited by a 980 nm diode laser. Two UC emission bands centered at 548 and 660 nm in the spectra can be assigned to ²H_11/2, ⁴S_3/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2 transitions of Er³⁺ ions, respectively. A Stokes infrared emission centered at 1530 nm is due to ⁴I_13/2 → ⁴I_15/2 transition of Er³⁺ ions. The dependence of UC emission intensity on pumping power indicates that the UC emission of the thin films is a two‐photon process. The thin films also exhibit a relatively high dielectric constant and a low dissipation factor as well as a good bias voltage stability. Temperature‐ and frequency‐dependent dielectric relaxation has been confirmed. This study suggests that Er³⁺/Yb³⁺ co‐doped Bi₂Ti₂O₇ thin films can be applied to new multifunctional photoluminescence dielectric thin‐film devices.     

Effect of Bi2O3 and B2O3 additives on the sintering temperature, microstructure, and microwave dielectric properties for Sm(Mg0.5Ti0.5)O3 ceramics

The microwave dielectric properties of Sm(Mg_0.5Ti_0.5)O₃ incorporated with various amount of Bi₂O₃ and B₂O₃ additives have been investigated systematically. In this study, both Bi₂O₃ and B₂O₃ additives acting as a sintering aid can effectively lower the sintering temperature from 1550 °C to 1300 °C. The ionic radius of Bi³⁺ for a coordination number of 6 is 0.103 nm, whereas the ionic radius of B³⁺ is 0.027 nm. Clearly, the ionic radius of Bi³⁺ is greatly larger than one of B³⁺, which resulted in the specimens incorporated with Bi₂O₃ having larger lattice parameters and cell volume than those incorporated with B₂O₃. The experimental results show that no second phase was observed throughout the entire experiments. Depending on the interfacial tension, the liquid phase may penetrate the grain boundaries completely, in which case the grains will be separated from one another by a thin layer as shown in Sm(Mg_0.5Ti_0.5)O₃ ceramics incorporated with Bi₂O₃. Whereas, in Sm(Mg_0.5Ti_0.5)O₃ ceramics incorporated with B₂O₃, the volume fraction of liquid is high, the grains may dissolve into the liquid phase, and rapidly rearrange, in which case contact points between agglomerates will be dissolved due to their higher solubility in the liquid, leading plate-like shape microstructure.A dielectric constant (?_r) of 29.3, a high Q × f value of 26,335 GHz (at 8.84 GHz), and a τ_f of −32.5 ppm/°C can be obtained for Sm(Mg_0.5Ti_0.5)O₃ ceramics incorporated with 10 mol% Bi₂O₃ sintered at 1300 °C. While Sm(Mg_0.5Ti_0.5)O₃ ceramics incorporated with 5 mol% B₂O₃ can effectively lower temperature coefficient of resonant frequency, which value is −21.6 ppm/°C. The Sm(Mg_0.5Ti_0.5)O₃ ceramic incorporated with heavily Bi₂O₃ and B₂O₃ additives exhibits a substantial reduction in temperature (∼250 °C) and compatible dielectric properties in comparison with that of an un-doped one. This implied that this ceramic is suitable for miniaturization in the application of dielectric resonators and filters by being appropriately incorporated with a sintering aid.     

Structural and electrical properties of (Bi0.9Dy0.1)(Fe0.975TM0.025)O3±δ (TM=Ni,Cr and Ti) thin films

Pure BiFeO₃ and rare earth and transition metal ions co-doped (Bi_0.9Dy_0.1)(Fe_0.975TM_0.025)O_3±δ (TM=Ni²⁺, Cr³⁺ and Ti⁴⁺) thin films were prepared on Pt(111)/Ti/SiO₂/Si(100) substrates by using a chemical solution deposition method. The changes in the microstructure and the electrical properties with doping elements were investigated. The thin films were well crystallized and randomly oriented, with no detectable impurity and secondary phases. The leakage current densities were reduced and the ferroelectric properties were improved in the co-doped thin films. Among the thin films, the (Bi_0.9Dy_0.1)(Fe_0.975Cr_0.025)O₃ thin film exhibited well saturated hysteresis loops with remnant polarization (2P_r) of 36 μC/cm² and coercive electric field (2E_c) of 954 kV/cm at 1000 kV/cm and low leakage current density of 1.91×10⁻⁵ A/cm² at 100 kV/cm. The enhanced properties observed in the co-doped thin films could be considered as being the result of the suppression of oxygen vacancies and of the modified microstructure.     

Improved photoelectrocatalytic degradation of methylene blue by Ti3C2Tx/Bi12TiO20 composite anodes

In order to effectively reduce the high recombination rate of photogenerated carriers when Bi₁₂TiO₂₀ (BTO) was excited by visible light, Ti₃C₂T_x/BTO/fluorine-doped tin oxide photoanodes were conveniently prepared with the aid of mechanical coating by gentle ultrasonic mixing. Systematic characterization and the degradation of methylene blue in a photoelectrochemical cell were performed. The results showed that the Ti₃C₂T_x/BTO composite exhibited a strong light absorption ability and the effective separation of photogenerated carriers. The optimal anode (6 wt% Ti₃C₂T_x/BTO) degraded 85.4% of methylene blue within 120 min at an applied electric field of 1 V, with a reaction rate that was 3.5 times that of BTO. It was proved that Ti₃C₂T_x, as a useful co-catalyst, creates an internal electric field at the contact interface with BTO and an external electric field, which are responsible for the enhanced photoelectrocatalytic degradation capacity of the composite anode materials.     

Dielectric Properties and Relaxation of Bi2Ti2O7

The dielectric properties of Bi₂Ti₂O₇ were explored as a function of temperature and frequency. A comparison between the dielectric response of the well‐known Bi_1.5Zn_0.92Nb_1.5O_6.92 (BZN) pyrochlore and the recently available Bi₂Ti₂O₇ sintered ceramic revealed considerable differences, which indicate that chemical disorder, and not atomic displacement on its own, is chiefly responsible for the dielectric relaxation in bismuth pyrochlores. A low‐frequency (<10 kHz) and relatively high‐temperature (~125 K) dielectric relaxation was observed in Bi₂Ti₂O₇. An Arrhenius function was used to model the relaxation behavior and yielded an activation energy of 0.162 eV and an attempt jump frequency of ~1 MHz. This response is consistent with space charge polarization and not the result of dipolar or ionic disorder.     

Facile synthesis,novel structure,multicolor luminescence,and potential applications of lanthanide ions doped bismuth titanate phosphors

A variety of lanthanide ions doped bismuth titanate (Bi₄Ti₃O₁₂) luminescent materials with eminent down-conversion (DC) and up-conversion (UC) luminescence performance have been fabricated via a facile sol-gel approach. The XRD, XPS, and EDX elemental mapping results confirm the phase structure of orthorhombic Bi₄Ti₃O₁₂ (BTO), and the lanthanide activator ions occupy the Bi³⁺ lattice sites in the BTO crystal. Under UV or NIR excitation, the Eu³⁺, Yb³⁺/Ln³⁺ (Ln = Er, Tm, and Ho) doped Bi₄Ti₃O₁₂ samples exhibit characteristic red, green, blue, and green emissions. The luminescent mechanisms of the BTO:Eu³⁺ and BTO:Yb³⁺/Ln³⁺ samples are discussed based on the energy level diagrams. The doping concentrations of Eu³⁺, Yb³⁺, Er³⁺, Tm³⁺, Ho³⁺ ions and annealing temperature and time are optimized, whose optimal values are determined to be 14, 8, 1, 0.4, 1 mol% and 800 ^oC, 4 h. The as-obtained LED devices fabricated by Bi₄Ti₃O₁₂:Eu³⁺ and Yb³⁺/Ln³⁺ phosphors exhibit dazzling multicolor visible light emissions from different Ln³⁺ ions. The results indicate that the as-obtained Ln³⁺ doped BTO phosphors may be potentially utilized in LED devices and solid-state lighting. Furthermore, the Eu³⁺ and Er³⁺ co-doped BTO samples exhibit different DC and UC luminescence spectral profiles when excited at various UV, visible, or NIR wavelengths, revealing their eminent feasibility and great potential in anti-counterfeiting applications.     

Solution-based fabrication and electrical properties of CaBi4Ti4O15 thin films

Ferroelectric CaBi₄Ti₄O₁₅ (CBT) thin films were prepared by spin coating technology using solution-based fabrication. The as-deposited CBT thin films were crystallized below 600 °C and the layered perovskite were crystallized at 700 °C using CFA processing in air. The enhancement of ferroelectric properties in CBT thin films for MFIS structures were investigated and discussed. Compared the Bi₄Ti₃O₁₂ (BIT), the CBT showed the better physical and electrical characteristics. The 700 °C annealed CBT thin films on SiO₂/Si substrate showed random orientation and exhibited large memory window curves. The maximum capacitance, memory window and leakage current density were about 250 pF, 2 V, and 10^?5 A/cm², respectively.