Recently, memristors have garnered widespread attention as neuromorphic devices that can simulate synaptic behavior, holding promise for future commercial applications in neuromorphic computing. In this paper, we present a memristor with an Au/Bi_3.2La_0.8Ti₃O₁₂ (BLTO)/ITO structure, demonstrating a switching ratio of nearly 10³ over a duration of 10⁴ s. It successfully simulates a range of synaptic behaviors, including long-term potentiation and depression, paired-pulse facilitation, spike-timing-dependent plasticity, spike-rate-dependent plasticity etc. Interestingly, we also employ it to simulate pain threshold, sensitization, and desensitization behaviors of pain-perceptual nociceptor (PPN). Lastly, by introducing memristor differential pairs (1T1R-1T1R), we train a neural network, effectively simplifying the learning process, reducing training time, and achieving a handwriting digit recognition accuracy of up to 97.19 %. Overall, the proposed device holds immense potential in the field of neuromorphic computing, offering possibilities for the next generation of high-performance neuromorphic computing chips.

The development of antiferroelectric materials with large energy density and fast discharge speed makes dielectric capacitors possess great prospects for applications in pulsed power technology. Here, the PbHfO₃-based ceramics with compositions of Pb(Hf_1-xTi_x)O₃ (PHT, 0.01 ≤ x ≤ 0.05) were synthesized, and their antiferroelectricity and phase transition behavior were studied. According to the tests of x-ray diffraction, dielectric spectrum, and polarization–electric field hysteresis loops, PHT ceramics gradually transition from an orthorhombic symmetric antiferroelectric phase to a hexagonal symmetric ferroelectric phase at room temperature as Ti⁴⁺ concentration increases. The forward phase switching field of antiferroelectric to ferroelectric phase transition can be markedly regulated by the introduction of Ti⁴⁺, and the optimal energy storage performance was obtained in Pb(Hf_0.98Ti_0.02)O₃ ceramics with a large recoverable energy storage density of W_rec ~ 4.15 J/cm³ and efficiency of η ~ 65.3% only at a low electric field of 190 kV/cm. Furthermore, the outstanding charge–discharge properties with an ultrafast discharge time (71 ns), remarkable discharged energy density (2.84 J/cm³), impressive current density (1,190 A/cm²), and ultrahigh power density (101 MW/cm³) at a low electric field of 170 kV/cm were obtained in studied ceramics. The excellent energy storage performance of PHT ceramics provides a promising platform for the application of dielectric capacitors.

BaTiO₃(BT) has attracted extensive attention among advanced lead-free ferroelectric materials due to its unique dielectric and ferroelectric properties. However, the enormous remanent polarization and coercive field severely impede the improvement of its energy storage capabilities. Here, the BaTiO₃Bi(Zn_0.5Hf_0.5)O₃ (BT-BZH) ceramics with high breakdown field strength and remarkable relaxation characteristics can be obtained by introducing the composite component BZH in BT to regulate the phase structure and grain size of the ceramics. The findings demonstrate that the improvement of energy storage performance is related to the increase of relaxation behavior. A large energy storage density (W_rec~3.62 J/cm³) along with superior energy storage efficiency (η~88.5%) is achieved in 0.88BT-0.12BZH relaxor ceramics only at 240 kV/cm. In addition, the sample suggests superior thermal stability and frequency stability within 25–115 ℃ and 1–500 Hz, respectively. Furthermore, the outstanding charge-discharge properties with an ultrafast discharge time (100 ns), large discharged energy density (1.2 J/cm³), impressive current density (519.4 A/cm²) and power density (31.1 MW/cm³) under the electric field of 120 kV/cm are achieved in studied ceramics. The excellent energy storage performance of BT-BZH ceramics provides a promising platform for the application of lead-free energy-storage materials.

Artificial synapse inspired by the biological brain has great potential in the field of neuromorphic computing and artificial intelligence. The memristor is an ideal artificial synaptic device with fast operation and good tolerance. Here, we have prepared a memristor device with Au/CsPbBr₃/ITO structure. The memristor device exhibits resistance switching behavior, the high and low resistance states no obvious decline after 400 switching times. The memristor device is stimulated by voltage pulses to simulate biological synaptic plasticity, such as long-term potentiation, long-term depression, pair-pulse facilitation, short-term depression, and short-term potentiation. The transformation from short-term memory to long-term memory is achieved by changing the stimulation frequency. In addition, a convolutional neural network was constructed to train/recognize MNIST handwritten data sets; a distinguished recognition accuracy of ~96.7% on the digital image was obtained in 100 epochs, which is more accurate than other memristor-based neural networks. These results show that the memristor device based on CsPbBr₃ has immense potential in the neuromorphic computing system.

More and more researchers start to pay attention to the electrocaloric temperature change (∆T) in polar materials, which is caused by an applied electric field. In this paper, Ba-doped PbHfO₃ (PBH) films were prepared by sol-gel method. Their components, microstructures, dielectric polarization and electrocaloric effects (ECEs) were investigated. With the addition of Ba²⁺, PBH films went from antiferroelectric (AFE) to ferroelectric (FE). At the same time, their dielectric peaks shifted toward lower temperature. The maximum ∆T obtained in Pb_0.8Ba_0.2HfO₃ FE film is 41.1 K, which is an order of magnitude larger than PbHfO₃ film (∆T ~ −4 K at 50 ℃) and Pb_0.9Ba_0.1HfO₃ film (∆T < 4 K at 120 ℃). In order to explain this phenomenon, the Landau-Devonshire theory was adopted. Our analysis shows that the rapid variation of energy barrier height near the phase transition temperature is beneficial to obtain large polarization change and high △T, which is needed in solid-state cooling devices.

The polycrystalline strontium ferrate titanate (SrFe_0.1Ti_0.9O₃, SFTO) thin films have been successfully prepared by chemical solution method. By analyzing the current-voltage (I-V) characteristics, we discuss the conduction mechanism of SFTO. It is found that the number of oxygen vacancy defects is increased by Fe ion doping, making SFTO be with better resistive switching property. Fe ion doping can also enhance the absorption of strontium titanate to be exposed to visible light, which is associated with the change of energy band. The band gap width (2.84 eV) of SFTO films is figured out, which is less than that of pure strontium titanate. Due to more oxygen vacancy defects caused by Fe ion doping, the band gap width of strontium titanate was reduced slightly. The defect types of SFTO thin films can be determined by electron paramagnetic resonance spectroscopy. In addition, we analyzed the energy band and state density of SFTO by first-principles calculation based on density functional theory, and found that Fe ion doping can reduce the band gap width of strontium titanate with micro-regulation on the band structure. A chemical state of SFTO was analyzed by X-ray photo electron spectroscopy. At the same time, the structure and morphology of SFTO were characterized by X-ray diffraction and scanning electron microscope. This study deepens further understanding of the influence of Fe ion doping on the structure and properties of strontium ferrate titanate, which is expected to be a functional thin film material for memristor devices.

Pb_xSr_1-xTiO₃ (x = 0.30, 0.35, 0.40, 0.45, 0.50 and 0.55) ceramics were fabricated by a solid-state reaction route. Xeray diffraction data at room temperature show PST samples shift from cubic to tetragonal phase with the increase of Pb²⁺ content. The microstructures were observed by scanning electron microscopy. Dielectric measurement was employed to investigate the ferroelectriceparaelectric phase transition behavior. Temperature dependent polarizationeelectric field hysteresis loops were conducted to study the electrocaloric effect (ECE) of the ferroelectric ceramics by indirect methods over a wide temperature range. Direct measurement of temperature change (ΔT) at room temperature for all samples can achieve 0.79–1.86 K. What's more, a giant ECE (ΔT = 2.05 K, EC strength (ΔT/ΔE) = 0.51 10^–6 K m/V, under 40 kV/cm) was obtained in the sample of x = 0.35 near phase transition temperature. Our results suggest that the ceramics are promising cooling materials with excellent EC properties for energy related applications.