Nowadays, the majority of the studies on the substitution are focused on cations (such as Y³⁺, Ti⁴⁺, P⁵⁺, etc.) in Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), while there are few studies on the substitution of anion O²⁻. In this work, the modified LATP with a series of LiCl (LATPClx, x = 0.1, 0.2, 0.3, 0.4) additives is prepared to enhance ionic conductivity. The successful introduction of Cl⁻ makes the length of the c axis decrease from 20.822(2) to 20.792(1) Å, and the bulk conductivity of 2.13 × 10⁻³ S·cm⁻¹ is achieved in LATPCl0.3. Moreover, the Al/Ti-O₁/Cl₁ and Al/Ti-O₂/Cl₂ distance decrease, while the Li₁-O₂/Cl₂ distance increases. Lithium ions migrate more easily in the nanochannel of M3-M1-M3. In addition, the LiCl additive increases the relative density and the grain boundary conductivity of LATPClx compounds. Naturally, a higher ionic conductivity of 2.12 × 10^–4 S·cm⁻¹ and a low activation energy of 0.30 eV are obtained in LATPCl0.3. Correspondingly, the symmetric cell exhibits a low overpotential of ±50 mV for over 200 h in LATPCl0.3. The solid-state Li|LATPCl0.3|NCM811 (NCM811 = LiNi_0.8Co_0.1Mn_0.1O₂) battery exhibits high initial capacity 185.1 mAh·g⁻¹ with a capacity retention rate of 95.4% after 100 cycles at 0.5 C. This result suggests that LiCl additive is an effective strategy to promote electrochemical properties of LATP solid electrolyte and can be considered for reference to other inorganic solid electrolytes systems.

Electro-optic modulators, which convert electrical signals onto the transmission light, are key devices in electro-optic modulating systems. Modulation efficiency is one of the most important parameters of an electro-optic modulator, which directly determines the footprint and power consumption of the device. Generally, modulation efficiency strongly depends on the electro-optic response of the crystal. The Pb(In_1/2Nb_1/2)O₃–Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ (PIN–PMN–PT) single crystal with giant electro-optic coefficient ( ${\gamma }_{\text{c}}$) and high transparency indicates the potential to achieve greatly enhanced modulation efficiency. In this study, a prototype PIN–PMN–PT phase modulator was fabricated based on a titanium (Ti) in-diffusion waveguide, which is reported for the first time. The influences of titanium in-diffusion on the composition and domain structure of the PIN–PMN–PT single crystal were studied by transmission electron microscopy (TEM) and piezoelectric force microscopy (PFM), respectively. Finally, a half-wave voltage (V_π) of 2.3 V was obtained using a device with 6-mm-long (L) electrodes. Furthermore, the electro-optic modulation efficiency (V_πL) was calculated as 1.38 V·cm, which was approximately one order of magnitude lower than that of commercial lithium niobate (LiNbO₃, LN) phase modulators. Such enhanced modulation efficiency indicates more compact device and lower power consumption, which is of great significance for electro-optic modulation systems used in micro-fiber gyroscope, integrated photonic devices, etc.

To further enhance the property of piezoelectric materials is of great significance to improve the overall performance of electro-mechanical devices. Here in this work, we propose a thermal annealing and high temperature poling approach to achieve significantly enhanced piezoelectricity in Pb(In_1/2Nb_1/2)O₃—Pb(Mg_1/3Nb_2/3)O₃—PbTiO₃ (PIN-PMN-PT) crystals with a morphotropic phase boundary (MPB) composition. The main idea of our approach is to realize a more sufficiently polarized crystal via active manipulation of defects and orientation of defect polarization. Manipulation of defect dipoles by the high temperature poling is proved by the piezo-response force microscopy. Finally, a d₃₃ of 3300 pC/N and a S_E of 0.25% are obtained, nearly 60% higher than that of conventionally poled crystals. Moreover, such a boosting of piezoelectric property is obtained under a maintained Curie temperature. Our research not only reveals the active control of defect dipole via modified poling method in the PIN-PMN-PT crystal, but also provides a feasible strategy to further improve the property of piezoelectric materials.

Herein, Ag_1-3xSm_xNbO₃ (0 ≤ x ≤ 0.025) antiferroelectric ceramics were successfully synthesized by solid state methods. The effect of Sm³⁺ doping on the structure, property and energy storage performance were studied. With the increasing Sm³⁺ concentrations, the average grain size decreased. Meanwhile, the stability of high temperature M phases (i.e., the structure between T_f and T₃) was expanded, which led to low loss for energy storage. Both of structure analysis and ferroelectric tests revealed the existence of weakly polar/AFE-like phase below T_f. The Sm³⁺ doping tended to suppress the ferroelectric behavior and expand the stability of antiferroelectricity. Consequently, a significantly enhanced energy storage performance (W_rec = 3.8 J/cm³, η = 73 %) could be achieved in Ag_0.97Sm_0.01NbO₃ ceramic, which was almost 1.5 times larger than that in non-doped AgNbO₃ (W_rec = 2.4 J/cm³, η = 45 %) under the similar applied field of 1705 kV/cm. In particular, the performance of the ceramic showed great temperature stability with variation of 5 % from 25 ℃ to 125 ℃. These results indicated that the Ag_0.97Sm_0.01NbO₃ ceramic could be an ideal lead-free candidate used in the energy storage field.