Na0.5Bi0.5TiO3 Research Articles

Low Sintering Temperature Effect on Crystal Structure and Dielectric Properties of Lead-Free Piezoelectric Bi0.5Na0.5TiO3-NaFeTiO4

Bi0.5Na0.5TiO3 (BNT) emerges as a promising ferroelectric and piezoelectric lead-free candidate to substitute the contaminant Pb[TixZr1−x]O3 (PZT). However, to obtain optimal ferroelectric and piezoelectric properties, BNT must be sintered at high temperatures. In this work, the reduction of sintering temperature by using iron added to BNT is demonstrated, without significant detriment to the dielectric properties. BNT-xFe with iron from x = 0 to 0.1 mol (∆x = 0.025) were synthesized using high-energy ball milling followed by sintering at 900 °C. XRD analysis confirmed the presence of rhombohedral BNT together with a new phase of NaFeTiO4 (NFT), which was also corroborated using optical and electronic microscopy. The relative permittivity, in the range of 400 to 500 across all the frequencies, demonstrated the stabilization effect of the iron in BNT. Additionally, the presence of iron elevates the transition from ferroelectric to paraelectric structure, increasing it from 330 °C in the iron-free sample to 370 °C in the sample with the maximum iron concentration (0.1 mol). The dielectric losses maintain constant values lower than 0.1. In this case, low dielectric loss values are ideal for ferroelectric and piezoelectric materials, as they ensure minimal energy dissipation. Likewise, the electrical conductivity maintains a semiconductor behavior across a range of 50 Hz to 1 × 106 Hz, indicating the potential of these materials for applications at different frequencies. Additionally, the piezoelectric constant (d33) values decrease slightly when low concentrations of iron are added, maintaining values between 30 and 48 pC/N for BNT-0.025Fe and BNT-0.05Fe, respectively.

Superior energy storage performance in NaNbO3‐based lead‐free ceramics under low electric field

AbstractNaNbO3 (NN)‐based materials have attracted widespread attention due to their advanced energy storage performance and eco‐friendliness. However, achieving high recoverable energy storage densities (Wrec) and efficiency (η) typically requires ultrahigh electric fields (E > 300 kV/cm), which can limit practical use. In this work, we present a synergistic strategy that employs the ferroelectric material Bi0.5Na0.5TiO3 (BNT) to augment the Pmax and the linear material Bi0.2Sr0.7TiO3 (BST) to optimize the P–E loops. Furthermore, a two‐step sintering process is implemented to preserve high Pmax values under lower electric field. As a result, ternary (1−x)(0.90NN‐0.10BNT)‐xBST was successfully prepared, achieving a high Wrec of 5.1 J/cm3 and a η of 85% in x = 0.20 samples at a low electric field of 290 kV/cm. Moreover, the x = 0.20 samples showed good frequency stability (1–200 Hz) and temperature stability (27°C–100°C). These results provide guidance for the development of ceramics with high energy storage properties under low electric fields.

Na0.5Bi0.5TiO3 as an efficient catalyst for degradation of Dyes, Cr (VI) reduction and biomedical applications

In present study, we prepared Na0.5Bi0.5TiO3 (NBTO3) having perovskite structure via solid-state route. NBTO3 sample was characterized to examine the physico-chemical, optical and photoelectrochemical assets of samples using various analytical techniques. Photocatalytic activity of NBTO3 was investigated for methylene blue and rose Bengal dye degradation and toxic Cr (VI) reduction. Furthermore, NBTO3 was evaluated for antimicrobial and antioxidant activity. These findings highlight the versatile role of the prepared NBTO3 as an efficient catalyst for environmental remediation making it a promising material for various applications. The rate and mechanism related with photodegradation reaction were evaluated by kinetics and radical trap based quenching experiment. Moreover, the reusability study confirmed that even after four cycles, the material’s photocatalytic activity was still high.

Design and electromagnetic shielding of Bi0.5Na0.5TiO3 ceramics as meta-surface absorber for high-frequency microwave application

EMI shielding reduces ambient electromagnetic (EM) radiation by reflecting and absorbing EM waves. Rapid technological growth has increased electronic gadgets and EM radiations, threatening the environment. Microwave materials with high absorption power and cheap cost are crucial for eliminating electromagnetic difficulties in stealth technologies. This study used a conventional solid-state reaction technique to prepare Bi0.5Na0.5TiO3 (BNT) solid solutions and examined their structural, ferroelectric, dielectric, and shielding characteristics. This research describes an EMI shielding material that efficiently absorbs EM wave-induced radiation. Characterizations have been done to evaluate material behavior to support EMI shielding and confirm its absorbing nature. Field emission scanning electron microscopy (FESEM), Raman spectroscopy, and X-ray diffraction (XRD) were employed to examine the surface morphology, local lattice deformation with ionic configuration, and crystal structure. BNT exhibited a rhombohedral structure with R3c symmetry space group with crystallize size 81.5 nm and showed eight Raman active modes with an average grain size of 1.67 μm. The high dielectric constant, reduced dielectric tangent loss, and enhanced polarization value make BNT ceramic a good choice for electrical devices and microwave applications. BNT ceramics showed EMI shielding owing to absorption (SET ∼ −23.65 dB, SEA ∼ −18.91 dB) at 9.2 GHz in the X-band (8.2–12.4 GHz). Meta-surface-based BNT absorbers were designed and simulated in the CST software. The peak depicted the absorption at 9.2 GHz with absorptivity of 91.56 %, 85.03 %, 84.36 %, and 64.6 % for designs 1, 2, 3, and 4, respectively. BNT ceramics have exceptional dielectric absorption properties, and dielectric and magnetic losses, which make them suitable for EMI shielding and absorption applications in the microwave region.

Component design for stabilizing P phase in NaNbO3-based ceramics and the energy storage performance

Antiferroelectric (AFE) ceramic dielectrics are widely recognized for their high potential in high-power pulse equipment applications. Lead-free NaNbO3 (NN) antiferroelectric ceramics have emerged as a prominent research topic in the field of energy storage due to their abundant phase structure, affordability, and moderate bandgap. The metastable ferroelectric Q phase results in a square hysteresis loop for NN at room temperature. However, 0.96NaNbO3-0.04 CaZrO3 (NNCZ) exhibits a typical double hysteresis loop at room temperature with the main crystalline phase being the antiferroelectric P phase, which has poor energy storage performance. In this study, Bi0.5Na0.5TiO3 (BNT) is used to optimize the energy storage performance and stabilize the P phase in NNCZ simultaneously. The dielectric constant and temperature-dependence XRD results that from −100 °C to 350 °C, x = 0.05 undergoes a phase transition from AFE P to AFE R and then to PE S. The solid solution of BNT decreased the sintering temperature of NN-based ceramics and decreased average grain size, thereby facilitating domain size reduction and improving the sample's energy storage efficiency from ∼30 % to ∼60 %, with an effective energy storage density reaching 1.51 J/cm3. The above results demonstrate that enhancing energy storage efficiency can be achieved through component design by reducing average grain size.

Superior energy storage performance of Sr0.7Bi0.2TiO3-modified Na0.5Bi0.5TiO3-K0.7La0.1NbO3 lead-free ferroelectric ceramics

Na0.5Bi0.5TiO3 (NBT)-based ceramics exhibit significant potential as energy storage dielectric materials due to their high maximum polarization (Pmax). However, their limited energy storage density significantly restricts their practical applications. To address this, this study optimizes the dielectric energy storage characteristics of lead-free relaxor ferroelectric ceramics based on 0.91Na0.5Bi0.5TiO3-0.09 K0.7La0.1NbO3 (NBT-KLN) by incorporating Sr0.7Bi0.2TiO3 (SBT) relaxor additives. The introduction of SBT helps maintain large polarization and induces local disorderly fields, promoting the formation of polar nanoregions. Subsequently, a viscous polymer processing (VPP) technique was employed to reduce defects and enhance density, markedly improving the breakdown strength (BDS). The findings indicate that the BDS of the optimized 0.30SBT (VPP) ceramics increased to 440 kV/cm, while achieving a high energy storage efficiency (η) of 78 % and an elevated energy storage density (Wrec) of 6.29 J/cm3. Additionally, the 0.30SBT (VPP) ceramics demonstrate excellent temperature stability across a broad temperature range from 30 to 120 °C, making them ideal for long-term operation in variable environments. This study demonstrates superior results compared to previous research, thereby opening up new avenues for developing novel lead-free relaxor ferroelectric ceramics with superior energy storage characteristics.

The structural evolution and electric field-induced strain performance of Bi0.5(Na0.41K0.09)TiO3–Ba(Fe0.5Sb0.5)O3 lead-free piezoelectric ceramics

In recent years, lead-free Bi0.5Na0.5TiO3 (BNT) based piezoelectric ceramics with excellent strain properties have gained widespread recognition for their application in high-precision displacement actuators. The (1-x)(0.82Bi0.5Na0.5TiO3-0.18K0.5Bi0.5TiO3)-xBa(Fe0.5Sb0.5)O3 ceramics were fabricated through the die-pressing method in this work. The effect of BFS introduction on the dielectric, ferroelectric and microstructure characteristics of BNKT ceramics was systematically investigated. Among these compositions, the BNKT-0.015BFS ceramics exhibited a piezoelectric strain coefficient (d33*) of 658 pm/V at an electric field of 55 kV/cm, while achieving a strain response of 0.51 % at 85 kV/cm. The observed improvement in strain performance can be attributed to the evolution from non-ergodic relaxor state to ergodic relaxor state caused by BFS substitution. Furthermore, transmission electron microscopy (TEM) explicitly confirmed coexistence of rhombohedral and tetragonal phase and revealed the morphology of nanosized domains. This study adds to a deeper comprehension of the characteristics of strain response enhancement in BNT-based ceramics, opening up avenues for designing novel lead-free piezoelectric ceramics with outstanding electromechanical performance.

Tailoring the structural and optical properties of lead-free Na0.5(Bi1-xSmx)0.5TiO3 multifunctional ceramics by Sm-doping

In this study, the effects of Sm3+-content on the structural and optical properties of the Na0.5(Bi1-xSmx)0.5TiO3 multifunctional lead-free system were investigated using x-ray diffraction (XRD), ultraviolet-visible (UV-Vis), Raman spectroscopy and photoluminescence (PL) spectroscopy. The Na0.5(Bi1-xSmx)0.5TiO3 (x = 0.000, 0.005, 0.010, 0.015, and 0.020) ceramics were synthesized by the solid-state reaction method with subsequent annealing. The Rietveld method was used to refine the XRD data. The results of these refinements indicated that pure NBT (Na0.5Bi0.5TiO3) and the Sm3+-doped samples showed the coexistence of the rhombohedral (R3c) and tetragonal (P4bm) phases in different fractions, which depend on the Sm3+-content. The UV-Vis data revealed that the optical band gap of the Na0.5(Bi1-xSmx)0.5TiO3 samples monotonically decreases with increasing Sm3+-content, providing evidence of replacement of Bi3+- by Sm3+-ions. Furthermore, Raman spectroscopy confirmed that substitution of Bi3+- by Sm3+-ions leads to a shortening of the Na/Bi-O bond length. It was demonstrated that this behavior is responsible for the increase in the local symmetry of the TiO6 octahedron and the consequent decrease in the ratio between both rhombohedral and tetragonal phases, as observed by the XRD data. The findings from the PL data revealed typical emissions corresponding to transitions between the 4G5/2 → 6Hj (j = 5/2, 7/2, 9/2, 11/2, 13/2) states of the Sm3+-ion. Additionally, the presence of non-radiative recombination processes was found to depend on both laser pumping power and Sm3+-content.

Enhanced photodielectric effect of Na1/2Bi1/2TiO3-based ceramics by poling and quenching treatment

The photodielectric effects of rare earth elements Er, Eu, and Ho doped Na1/2Bi1/2TiO3 (NBT) ceramics are investigated. The dependence of light intensity and irradiation time on the photodielectric effects were clarified, and the thermal-induced and photo-induced changes in permittivity are distinguished. At 1 kHz, the Δεr/εdark (Δεr = εphoto-εdark) of NBT-Er/Eu and NBT-Er/Ho are 2.57 % and 2.08 %, respectively. Furthermore, poling and quenching treatments are employed to improve the photodielectric effect of NBT-Er/Ho ceramics. At 1 kHz, the Δεr/εdark of poled and quenched NBT-Er/Ho increase to 5.22 % and 2.71 %, respectively. The increase of Δεr/εdark of poled sample is resulted from the lattice distortion of the ceramics while the increase of Δεr/εdark of quenched sample is due to the increase in oxygen vacancies. This work is conducive to understand the unconventional optical and dielectric effects in ferroelectric ceramics.

Diffusosphere engineering in BNT-based multilayer heterogeneous film capacitors for high performance

Combining layers with high breakdown resistance and high polarization is a promising approach for designing dielectric capacitors with high energy density and efficiency. However, such combinations often accompany strong interfacial polarization, magnification of local electric fields, leading to premature breakdown. This work addresses this issue via controlled formation of diffusospheres. We constructed multilayer heterogeneous films using two Bi0.5Na0.5TiO3 (BNT)-based substances with high breakdown resistance and high polarization properties. Experimental results and finite element simulations demonstrate that the energy storage capacity of these films effectively harnesses the advantages of both phases. Notably, the interface polarization is minimal. Instead, a solid solution-like diffusosphere, formed by the mutual diffusion of ions between the two phases, plays a crucial role. The diffusosphere acts as a transition zone, mitigating charge aggregation at the interfaces and optimizing the relaxor and breakdown characteristics of the capacitor. With six diffusospheres, the multilayer heterogeneous capacitor achieves a recoverable energy storage density of 94 J/cm3, a significant advancement in BNT-based energy storage films. This work proposes and validates the concept of diffusospheres and their role in reducing interfacial polarization in multilayer heterogeneous films, enhancing the understanding of heterogeneous composite structures and advancing the field of dielectric energy storage.

Effects of thickness and defect on ultrahigh electro strain of piezoelectric ceramics

Piezoelectric ceramics with high electro strain are widely used in actuators, sensors, and so on. Here, this work investigates the electro strain of representative piezoelectric materials, and analyzes the influence of electrode type on the electro strain of PZT41 with significant strain anomalies. It is found that the occurrence of abnormally significant strain is not affected by the electrode but caused by intrinsic defects. Therefore, the ceramic samples with and without defects tailoring in Na0.5Bi0.5TiO3 (NBT) based and PbZr0.52Ti0.48O3 (PZT) based systems were prepared by the solid-state reaction method, and the results show that abnormally ultrahigh electro strains occur in excessively thin samples with diploes due to defects tailoring. Through displacement configuration experiments and comprehensive analysis of polarization switching processes, it is found that the occurrence of asymmetric abnormal significant strains is caused by reversible bending deformation in excessively thin samples. This work provides new support for the emergence of ultrahigh electro strain in piezoelectric ceramics.

Nb/Mn co‐doping enhances the pyroelectric properties of Na0.5Bi4.5Ti4O15 ceramics for infrared detection

AbstractThe pyroelectric effect has wide applications in various fields, such as infrared imaging, detection, alarms, and the expanding field of smart homes. The rapid advancement of smart systems, focusing on miniaturization and integration, requires pyroelectric infrared detectors with high pyroelectric coefficients and Curie temperatures to meet the requirements of integrated processes. However, the Curie temperature of commercial lead zirconate titanate is limited to <230°C, urgently looking for a breakthrough. Here, we explore pyroelectricity in Na0.5Bi4.5Ti4O15 (NBT) ceramics, characterized by a high Curie temperature (∼660°C). We systematically examined the crystal structure modifications and defect dipole effects of the Nb/Mn‐co‐doped NBT. The lattice expansion, distortion of the TiO6 octahedra, and structural transformation tendency from the orthorhombic to tetragonal phase facilitate dipole movements with increasing temperature. Furthermore, the Mn and Nb elements result in the formation of MnTi“–VO·· and NbTi·–MnTi” –NbTi· defect dipoles, inducing additional polarization changes in response to temperature variations. Finally, a significantly improved pyroelectric coefficient of 110 µC m2 K–1 and remarkable temperature stability from 25°C to 300°C is achieved in NBTM‐5Nb ceramics. This co‐doping strategy for enhancing pyroelectric performance can be expanded to other systems and substantially contribute to advancing high‐performance materials for infrared detection.

Superior dielectric energy storage performance of ultrafine-grained BNT-SBT solid-solution ceramics by solution combustion synthesis

The micrometer scale grain size and large remnant polarization of Bi0.5Na0.5TiO3 (BNT) ferroelectric ceramics severely constrain the breakdown strength and energy efficiency, respectively, restricting their energy storage application despite their large polarization. Hereby, superior energy storage performance is reported by a synergistic strategy of introducing Sr0.7Bi0.2TiO3 (SBT) relaxor ferroelectrics and a solution combustion synthesis (SCS) method. The BNT-SBT solid-solution ceramics are comparatively investigated by the two methods, conventional sintering (CS) and SCS. An ultrafine average grain size of ∼0.39 μm was obtained in the SCS-derived ceramic, and thus exhibits an ultra-high critical electric field of 548 kV/cm, and a high recoverable energy density of ∼5.69 J/cm3. Those key energy storage parameters are superior to those of the previous reported samples prepared by the CS method. Meanwhile, a high energy efficiency ∼90 %, a large power density of ∼130.44 MW/cm3 (at 320 kV/cm), and an ultrafast discharge time of ∼61.7 ns are also achieved. This study indicates that grain engineering combing with chemical design is an effective way to enhance the dielectric energy storage performance.

Solid state synthesis of lead-free Sm-doped Na0.5Bi4.5Ti4O15 ceramics for enhanced dielectric and electrical properties

Here we report the synthesis of Sm-doped Na0.5Bi4.5Ti4O15 (Na0.5Sm0.5Bi4Ti4O15) lead-free ceramics via a conventional solid-state technique. Investigations of Na0.5Bi4.5Ti4O15 (NBT) and Na0.5Sm0.5Bi4.5Ti4O15 (NSBT) ceramics were demonstrated in detail to understand the composition-based structure-property of Aurivillius compounds and related functional material. Dielectric properties for frequency and temperature in a wide range were analyzed. The conduction activation energy values of NSBT ceramics are obtained to be 1.40 eV, whereas, the NBT ceramics get the value to be 1.31 eV. At higher temperatures, the conduction activation energy value of NSBT ceramics is 1.32 eV for both frequencies of 100 Hz and 1 kHz, whereas, for NBT compounds, the calculated value is 1.27 eV for both frequencies. The simulation performed on the impedance data for capacitive and resistance elements shows well-fitting curves which indicates a single relaxation behavior in the material. Similarly, the AC-conductivity data were analyzed which gives different conduction processes and relaxation activation energies in the NSBT ceramics.

Optimized pyroelectric behaviors by constructing the nonergodic-ergodic transition state

Bi0.5Na0.5TiO3 (BNT)-based relaxors are considered as potential candidates for pyroelectric applications due to their excellent pyroelectric performances. However, the excellent pyroelectric response in BNT-based relaxors is generally accompanied by a rapid decrease in the depolarization temperature Td, limiting the operation temperature. Herein, we find that the mixed non-ergodic and ergodic relaxor states (a kind of transition system) can promote polarization rotation and remain the reversibility of polarization transformation simultaneously, thereby improving pyroelectric performances and maintaining the Td . The Li+-doped BNKT-based relaxors which possess such a transition state exhibit excellent room temperature (RT) pyroelectric coefficients (1247 μCm−2K−1), and also, the Td can maintain at 69℃. This work provides a strategy for further insight into the enhanced pyroelectric response, which promotes the development of eco-friendly pyroelectric applications (such as infrared detection, temperature sensors, and pyroelectric energy harvesting).

Effects of annealing temperature and ion doping on energy storage performance of Na0.5Bi0.5TiO3-Based thin films

Lead-free ferroelectric thin film capacitors offering superb power density and fast charge-discharge rates are ideal for energy storage applications. However, the trade-off relationship between polarization strength and breakdown strength significantly hinders the improvement of energy storage performance. In this work, relaxor-ferroelectric Na0.5Bi0.5TiO3 (NBT) thin films have been deposited on Pt/Ti/SiO2/Si substrate via sol-gel method. First, the energy storage performance of the films is optimized by adjusting the annealing temperature. It is found that the NBT film annealed at 650 °C has both excellent breakdown strength and polarization strength. Then the influence of ion doping on the energy storage performance of NBT films has been studied. An excellent energy storage density of 42.1 J/cm3 and efficiency of 55.8 % are simultaneously achieved in the 2 % Mn-NBT thin film. Additionally, the energy storage performance remains stable within the temperature range of 25–180 °C and frequency range of 500–5000 Hz. The energy storage performance of 2 % Mn-NBT thin film did not decrease significantly after 107 electrical cycles. It is predicted that this work will advance the utilization of Na0.5Bi0.5TiO3-based film capacitors in energy storage systems.

Development of new lead free ceramic substrate for rectangular patch antenna application in X-band communication

This work introduces the use of Bi0.5Na0.5TiO3 (BNT) ceramic material as substrates for microstrip patch antennas operating within the frequency range of 8-12 GHz. The simulated antenna was constructed using a substrate composed of a synthesized ferroelectric perovskite-based material with a thickness of t=1.02 mm. This study investigated the intricate electromagnetic properties including permittivity, permeability, dielectric loss, magnetic loss, and miniaturization factor. Characterization techniques are used to investigate the crystal structure, local vibrational properties, surface morphology, and elemental composition of the synthesized sample. The reflection loss, return loss, and radiation pattern of the split ring microstrip patch antenna with a rectangular base were calculated using CST Microwave Studio version 2019. The parametric adjustment of the synthesized sample's uniqueness was achieved by modifying its thickness for t=0.7 mm, t=0.9 mm, t=1 mm, t=1.02 mm, and t=1.04 mm.

Investigations of energy storage and thermal stability properties in eco-friendly B-site substituted Na0.5Bi0.5TiO3

In this work, (Mg1/3Nb2/3)4+ cationic substitution in lead-free polycrystalline Na0.5Bi0.5TiO3 (NBT) has been adopted to synthesize by the conventional solid-state reaction method. The cationic substitution was introduced into NBT through compositional modification, which significantly restricted grain growth and promoted a ferroelectric to relaxor ferroelectric phase transition. The substitution of (Mg1/3Nb2/3)4+ influenced the crystal structure, ferroelectric, dielectric properties, and micromorphology, which had been investigated systematically. The enhancement of relaxor nature is found with this substitution and further verified by dielectric curve, polarization (P) - electric field (E) hysteresis loop, and current (I)- electric field (E) curve. The recoverable energy density was determined to be 1.09 J/cm3 and 1.24 J/cm3 at 101 kV/cm and 114 kV/cm in the 10 mol% and 20 mol% of (Mg1/3Nb2/3)4+ substituted systems, respectively. Furthermore, over the 35 ˚C to 490 ˚C temperature range, the 30 mol% (Mg1/3Nb2/3)4+ substituted composition showed superior thermal stability in the permittivity. Therefore, this study concluded that these cationic substituted NBT compositions are appropriate materials for applications involving higher-temperature and energy storage in electronic devices.

The influence of thermo-electromechanical coupling on the performance of lead-free BNT-PDMS piezoelectric composites

In recent times, there have been notable advancements in haptic technology, particularly in screens found on mobile phones, laptops, light-emitting diode (LED) screens, and control panels. However, it is essential to note that the progress in high-temperature haptic applications is still in the developmental phase. Due to their complex phase and domain structures, lead-free piezoelectric materials such as Bi0.5Na0.5TiO3 (BNT)-based haptic technology behave differently at high temperatures than in ambient conditions. Therefore, it is essential to investigate the aspects of thermal management and thermal stability, as temperature plays a vital role in the phase and domain transition of BNT material. A two-dimensional thermo-electromechanical model has been proposed in this study to analyze the thermal stability of the BNT-PDMS composite by analyzing the impact of temperature on effective electromechanical properties and mechanical and electric field parameters. However, the thermo-electromechanical modelling of the BNT-PDMS composite examines the macroscopic effects of the applied thermal field on mechanical and electric field parameters, as phase change and microdomain dynamics are not considered in this model. This study analyzes the impact of thermo-electromechanical coupling on the performance of the BNT-PDMS composite compared to conventional electromechanical coupling. The results predicted a significant improvement in piezoelectric response compared to electromechanical coupling due to the increased thermoelectric effect in the absence of phase change and microdomain switching for temperature boundary conditions below depolarization temperature ( Td∼200∘ C for pure BNT material).

The effects of crystal orientation on the ferroelectric and optoelectronic properties of Pt/Na0.5Bi0.5TiO3/La0.5Sr0.5CoO3 heterostructures

Due to their excellent ferroelectric, semiconducting, and optoelectronic properties, perovskite ferroelectric thin films have attracted increasing attention in the photovoltaic field. Using La0.5Sr0.5CoO3 (LSCO) as the bottom electrode, flake, strip and pyramidal Na0.5Bi0.5TiO3 (NBT) films were prepared on (001), (110) and (111) SrTiO3 (STO) substrates by off-axis magnetron sputtering and pulsed laser deposition, respectively. XRD and Phi scan results show that both LSCO and NBT are perovskite structures and satisfy the epitaxial growth along the substrate STO. NBT orientation has a significant effect on the ferroelectric properties of Pt/NBT/LSCO heterostructures. The remnant polarization 2Pr values for NBT(111), NBT(110) and NBT(001) are 87.5, 62.6 and 28.5 μC/cm2, respectively, and thus 2Pr(111)>2Pr(110)>2Pr(001). NBT(111) shows the best ferroelectric properties (Pr=41.3 μC/cm2), excellent fatigue-resisting (up to 1010 cycles) and retention performance (duration 104s). The 2Pr-T association 2 Pr=41.72+16.05*T0.35 for NBT(111) was obtained according to the curve fitting, it is found that the NBT orientation has a significant effect on the PV effect for PT/NBT/LSCO photovoltaics and the open-circuit voltage ∆Voc. The short-circuit current ∆Jsc of polarization regulate intensity follows the laws of ∆Voc-111>∆Voc-110>∆Voc-001 and ∆Jsc-111>∆Jsc-110>∆Jsc-001, the Jsc for Pt/NBT(111)/LSCO heterostructures increases linearly with the illumination Ip increasing, while the Voc decreases linearly. The ferroelectro-polarized modulation PV mechanism was investigated by analyzing band structure of the Pt/NBT/LSCO heterostructures, which is attributed to the coupling effect of the ferroelectric depolarization field and the interfacial Schottky barrier.