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Mercury cadmium telluride compounds exhibit large tunability of nontrivial electronic states by modifying chemical composition, temperature, or pressure. Despite the growing interest in Hg1–xCdxTe, very little information currently exists on how their electrical properties are affected upon compression. Here, we systematically investigate the high-pressure behaviors of bulk Au-doped Hg0.781Cd0.219Te crystals with the doping level close to the Kane fermion point. A clear structure evolution path of this compound with pressure varying from zinc blende (F43̅m) through cinnabar (P3121) and rocksalt (Fm3̅m) to the orthorhombic one (Cmcm) is established from the measurements of phonon spectra, resistivity, and the Hall effect. Pressure-induced phonon softening is proposed to be the driving force for the phase transition. The last two phases are found to exhibit superconductivity with different pressure dependence of the critical temperature. These results and findings suggest that superconductivity is the general nature of mercury cadmium tellurium compounds at high pressures. The group II–VI compounds thus also offer a pool for finding new superconductors.

Recent studies demonstrate that 2H-WS2is an excellent candidate for further applications in the electronics, spintronics, and optoelectronics. The details of phonon scattering processes associated with the thermal properties of a material are crucial for commercial applications. Here, we report an experimental study of the temperature-dependent Raman spectra of 2H-WS2over a wide range from 3.6 to 850 K. The nonlinear temperature-dependent behavior corresponding to the phonon anharmonicity is estimated from both the frequency and linewidth of E2g2, E2g1, and A1gmodes. It is found that the three-phonon process is dominant in the phonon softening and linewidth broadening in the whole temperature range. The four-phonon process can be detected and is even stronger than the three-phonon process at high temperatures. The obtained E2g1mode is insensitive to the anharmonic effect, whereas the E2g2mode is most sensitive. The phonon anharmonicity is suggested to mainly originate from the interaction between acoustic phonon and optical phonon. Understanding the phonon anharmonicity in 2H-WS2is helpful for further applications of nanodevices.

Titanium (Ti) and its alloys have been widely used in orthopedic and dental applications. The bonding between Ti implants and tissues is significantly important in the clinical applications, which is highly relative to the characteristics of implant surface with surface improvement by various coatings such as hydroxyapatite (HA). Meanwhile, the characteristics of modified implants surface can induce special biological response of osteogenic cells to improve the bone-implant bonding. In this paper, in order to improve Ti bioactivity and enhance its osteointegration, calcium phosphate (CaP)/titanate coatings were prepared on Ti with nanoscale surface topographies by a two-step hydrothermal process. Firstly, titanium meshes were treated in sodium hydroxide solutions at two temperatures (200 °C or 240 °C). Then, the treated meshes were immersed in calcium phosphate solutions containing various concentrations of cyclohexane-hexacarboxylic acid (H6L) under hydrothermal conditions. After this two-step process, calcium phosphate deposits, confirmed to be apatite/titanate by energy dispersive X-ray spectroscopy, were successfully formed on the treated Ti mesh surface. These results suggested that this two-step hydrothermal method can be successfully applied to fabricate robust and hierarchical nanostructured coatings of CaP/titanate on Ti implants.

Since rubber was applied in people’s normal life, researchers have started to exploit the rubber reinforcing techniques and the relative mechanism. Developing high-effective, simple and economical reinforcing methods and fillers are the emphasis of rubber industry, technology and science. In this paper a rubber ideal filler (IF) is shown. This IF is a kind of composite with core-shell structure which was synthesized by seeded emulsion polymerization. It used styrene (St), polybutadiene oligomer (PBD) as monomers and divinyl benzene (DVB) as cross-linking agent. The effect of the amount of cross-linking agent, concentration of emulsifier and initiator on the stability of the emulsion was studied. The morphology of the latex particles with core-shell structure was characterized by high resolution SEM (ESEM) and DSC (Tg). The results showed that cross-linking polymeric particles exhibited strong reinforcing effect on styrene-butadiene rubber (SBR).