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High-quality fine-grained ferroelectric glass-ceramic composites were successfully fabricated by using a modified hybrid processing. The properties of interfaces were investigated by using impedance spectroscopy (IS). In our measured impedance spectra, a polarization with an ideal Debye behavior was observed at intermediate frequency ranging between 1 kHz and 100 kHz. This polarization was attributed to the space charge accumulation at the grain-boundary interfaces, due to the presence of large dielectric constant difference between the fillers and the host. Basing on the IS results, a brick-layer microstructural model was proposed for the ferroelectric glass-ceramic composites. Our studies indicated that the new modified hybrid processing can be used to design composites with desired interfaces that have a homogeneous dielectric constant, so as to achieve high breakdown strength, thus leading to high electrical energy density storage devices.

Zn2+ ion substituted nickel ferrite nanomaterials with the chemical formula Ni1−xZnxFe2O4 for x = 0, 0.3, 0.5, 0.7 and 1 have been synthesized by a facile green-chemical hydrothermal method as anode materials in lithium ion battery. The morphology and structure of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The physical and electrochemical properties were tested by electrochemical system. Furthermore, the energetic and electronic properties of the samples were investigated by density functional calculations. The results suggest that Zn substitution can affect the conduction performance of the zinc - nickel ferrite. Meanwhile, electrochemical results show that an enhancement in the capacity with increasing Zn concentration is observed especially for x = 0.3 which exhibit high discharge capacity of 1416 mAh g−1at the end of 100th cycle. Moreover, the theoretical research method with high yield synthesis strategy described in the present work holds promise for the general fabrication of other metallic elements substitution in complex transition metal oxides for high power LIBs.

Using LiF and PbF 2 (mole ratio 1:1, LPF) as sintering additives, the x CoFe 2 O 4 /(1 − x ) Pb 0.9025 La 0.065 (Zr 0.58 Ti 0.42 ) 0.975 Nb 0.02 O 3 [ x = 0.1, 0.2, 0.3, and 0.4 in weight] (abbreviate as CFO/PLZT) 0–3 magnetoelectric (ME) composite ceramics were developed via a liquid phase sintering technique. A ZrO 2 layer was coated on the CFO particles via a sol–gel method in order to inhibit the diffusion of Fe 3+ and Co 2+ ions from the ferrite CFO phase to the ferroelectric PLZT phase. With using 6 wt% additives of LPF, dense composite ceramics can be obtained in a sintering temperature region of 1000–1150 °C for 30 min. Moreover, overall performance of the ceramics with relatively low CFO content ( x = 0.2) has been optimized. The effects of CFO content and sintering temperature on micromorphology, crystalline structure, piezoelectric, dielectric, and ME properties were investigated. It was found that the 0.2CFO/0.8PLZT composite ceramics exhibited a d 33 of 80 pC/N and a ME coefficient of 102 mV/Oe cm at 215 kHz.

MnO-doped 0.97K 0.5 Na 0.5 NbO 3 –0.03(Bi 0.5 K 0.5 )TiO 3 lead-free piezoelectric ceramics have been fabricated by solid state reaction. The MnO-doped KNN-BKT samples show tetragonal perovskite structure and the grain size increases obviously. With an addition of the optimal doping of MnO, all the electrical properties of the samples, especially the piezoelectric and pyroelectric performance, have been enhanced significantly. The KNN-BKT ceramics, with 0.8 wt% MnO doping, exhibits optimal electrical properties: d 33 = 221 pC/N, k p = 44.7%, tgδ = 1.4%, ɛ r = 1229, Q m = 143, ρ = 4.464 g/cm 3 and p = 221 μC/m 2 K.