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A novel chromium carbide–nickel composite was in situ fabricated through pressureless sintering in a vacuum furnace using Cr, C, Ni and Mo mixed powders. In this study, the Mo content distribution on interface characterization including the effect of phase transformation mechanism and mechanical properties of the composite were researched thoroughly. The results indicated that a newly found and excellent semi-coherent boundary existed between Cr3C2 and Ni, which was (002)Cr3C2//(11 1 ( _ ) )Ni, [1 2 ( _ ) 0]Cr3C2//[011]Ni. Their disregistry along the particular orientation relationship was approximately 10.6%, indicating that Cr3C2 could serve as an efficient heterogeneous nucleation area of Ni. An interdiffusion and phase transformation occurred in the microstructure, Mo element tended to solid solute into the carbide matrix which changed from (Cr, Ni)3C2 to (Cr, Mo)3C2, and (Cr, Mo, Ni)7C3. Moreover, according to DFT calculation for contain phases as well as the Rockwell hardness, bending strength, and fracture roughness were enhanced simultaneously, it was attributed to grain refinement, solution strengthening, and better mechanical properties of the (Cr, Mo, Ni)7C3 phase.

The effects of the electrode-bulk interface on the dielectric properties of Ba0.9988Bi0.0008Zr0.2Ti0.8O3 (BBZT) ceramics with a slight change in the thickness (≤15%) were investigated. In BBZT ceramics, the dielectric constant decreases with the increase of thickness, and the interface between electrode and bulk ceramics is considered the main reason. A formula is proposed to calculate the dielectric constant of bulk materials. According to the formula, the electrode-bulk interface has a slight influence on the frequency characteristics of the dielectric constant. However, the ferroelectric to paraelectric phase transition temperature changes from 10 °C to 15 °C for bulk ceramics when the electrode-bulk interface is taken into consideration. In a range of 0 °C–75 °C, obvious differences between eB and eT are observed due to the electric field induced by removable carriers. The dielectric tunability is degraded by the influence of electrode-bulk interface. BBZT ceramics have considerable tunability (>65% @100 kHz) and a low loss tangent ( 270). This study demonstrates a method of calculating the dielectric constants of bulk ceramic layers and provides a theoretical basis for improving the performance of bulk materials using interfacial layers.

A lithium disilicate (LD) glass with stoichiometric composition and glass transition temperature (Tg) ∼ 470 °C was ion-exchanged over a wide temperature range below the Tg. The ion-exchange temperatures used were 380 °C or 315 °C in a pure molten NaNO3 bath, and 235 °C in a molten mixed salt bath of 50 mol% NaNO3＋50 mol% KNO3. Temperature-dependences of surface layer morphology and mechanical behavior of the ion-exchanged glass were investigated. It was found that similar surface Na+ concentrations were presented on the glass after the ion-exchange at all the three temperatures for different times. Surface failure occurred on the glass after the treatments at the two higher temperatures for longer time to increase the ion-exchanged depth. The surface failure could be completely avoid by substantially lowering the temperature to 235 °C in the mixed salt bath for much longer time to obtain a similar level of case depth. Similar strengthening effects were exhibited at the three temperatures as the ion-exchanged depth was shallower. With further increasing the depth, however, much more significantly strengthening effect could be achieved at the substantially lowered temperature. Flexural strength of the glass could be enhanced from ∼ 97 MPa to ∼ 520 MPa after the treatment at 235 °C for 128 h. The temperature-dependent effect to strengthen the LD glass by Li+/Na+ exchange was attributed to the combined effect of stress relaxation during ion-exchange and thermal contraction coefficient mismatch between the ion-exchanged surface layer and the internal bulk glass.

Herein, a novel hierarchical TiO2 pinecone-like structure (TPS) has been successfully fabricated for the first time by self-assembling anodic oxidation methods on the Ti plate. Then it was constructed that a series of CdS-TPS nanocomposites with different cycles CdS modifying by a successive ionic layer adsorption and reaction (SILAR) after different temperature annealing in air. The structures and properties of the CdS-TPS were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Current-voltage (I-V), ultraviolet-visible (UV–vis/DRS). The results shown that the optical properties of the CdS-TPS could be rationally tailored by adjusting the CdS-modified cycles and annealing temperature, which significantly enhanced photocatalytic activity. To be used in photocatalytic organic pollutant removal after optimizing both the CdS modification cycles and annealing temperature. The 15-CdS-TPS-500 °C exhibited significantly improved photocatalytic activities of methyl orange (MO) degradation under simulated sunlight irradiation. With 180 min, 85% of the MO (0.05 mM/L, 5 mL) was photodegraded and its kinetic constant reached to 0.0104 min−1, which is the 3.0 times and 3.6 times quicker than that of 5-CdS-TPS-500 °C and 15-CdS-TPS-0 °C, respectively. This could be ascribed to the result of the synergy effects of the suitable quantity of CdS nanoparticles modifier, the special surface structure, excellent crystallinity, higher electrical conductivity, and band structure matching. The possible photocatalytic mechanism of the CdS-TPS sample is investigated as well.

Lead-free barium tin titanate BaTi 0.85 Sn 0.15 O 3 (BTS) ferroelectric thin films have been deposited on Pt/Ti/SiO 2 /Si substrates by pulsed laser deposition. The structure and dielectric properties of thin films deposited at various oxygen pressures are investigated systematically. By optimizing the oxygen pressure during the deposition, the structure and dielectric properties are improved. The thin films grown at 15 Pa have the best crystal quality and the largest grain size, which result in the enhancement of the dielectric properties. The dielectric constant and loss tangent show the similar trend in the entire oxygen pressure range. The influence mechanisms of the oxygen pressure on the structure and dielectric properties are proposed. The BTS thin films deposited at 15 Pa with large figure of merit (FOM) of 81.1, high tunability of 72.1%, moderate dielectric constant of 341, low loss tangent of 0.009 are considered to be appropriate as a field tunable ferroelectric material for electrically tunable devices.

Mn-Based thin film thermistors with a sandwich structure were prepared on Pt/TiO 2 /Ti/SiO 2 /Si substrates by a chemical solution deposition method and annealed at different temperatures (600, 650, 700 and 750 °C). Effects of annealing temperature on microstructure and electrical properties of the prepared thin film thermistors were investigated in detail. The results showed that the degree of crystallization and grain size was enhanced; the resistivity and the aging coefficient were decreased with the increase of annealing temperature. The carrier concentrations were not affected by the annealing temperature. The thin film thermistor annealed at higher temperature has larger value of dielectric permittivity at low frequencies, while it has smaller value of dielectric permittivity at high frequencies than those thin film thermistor annealed at lower temperature.