Record high T element superconductivity achieved in titanium.

It is challenging to search for high T superconductivity (SC) in transition metal elements wherein d electrons are usually not favored by conventional BCS theory. Here we report experimental discovery of surprising SC up to 310 GPa with T above 20 K in wide pressure range from 108 GPa to 240 GPa in titanium. The maximum T above 26.

Preventive effect of surface charge on encrustation of biodegradable ureteral stents.

Prevention of encrustation on the surface has always been the biggest challenge for urological implants. In the field of ureteral stent design, biodegradability has attracted much attention in recent years, because biodegradable ureteral stents not only avoid secondary intervention, but also prevent encrustation due to surface renewal by degradation process. Furthermore, researches have focus on some surface parameters to provide guidance for the development of stent materials, such as hydrophilicity or surface charge.

Superconductivity above 200 K discovered in superhydrides of calcium.

Searching for superconductivity with T near room temperature is of great interest both for fundamental science & many potential applications. Here we report the experimental discovery of superconductivity with maximum critical temperature (T) above 210 K in calcium superhydrides, the new alkali earth hydrides experimentally showing superconductivity above 200 K in addition to sulfur hydride & rare-earth hydride system. The materials are synthesized at the synergetic conditions of 160~190 GPa and ~2000 K using diamond anvil cell combined with in-situ laser heating technique.

Tuning the mechanical properties and degradation properties of polydioxanone isothermal annealing.

Polydioxanone (PPDO) is synthesized by ring-opening polymerization of p-dioxanone, using stannous octoate as the catalyst. The polarized optical micrograph (POM) shows thes pherulite growth rate of PPDO decreases with an increase in the isothermal crystallization temperature. PPDO is compression-molded into bars, and PPDO bars are subjected to isothermal annealing at a range of temperatures (Ta = 50, 60, 70, 80, 90, and 100 °C), and correspond to three different annealing times (ta = 1h, 2h, 3h).

BaVSe: a novel compound with spin chains.

In this work, a novel compound BaVSe with one-dimensional (1D) spin chains was synthesized under high-pressure and high-temperature conditions. It was systematically characterized via structural, magnetic, thermodynamic and transport measurements. BaVSe crystallizes into a hexagonal structure with a space group of P-6c2 (188) and the lattice constants of a  =  b  =  9.

Synthesis, Structure, and Properties of the Layered Oxyselenide BaCuOCuSe.

A new layered oxyselenide, BaCuOCuSe, was synthesized under high-pressure and high-temperature conditions and was characterized via structural, magnetic, and transport measurements. It crystallizes into space group I4/ mmm and consists of a square lattice of [CuO] planes and antifluorite-type [CuSe] layers, which are alternately stacked along the c axis. The lattice parameters are obtained as a = b = 4.

Charge Transfer Induced Multifunctional Transitions with Sensitive Pressure Manipulation in a Metal-Organic Framework.

The metal-organic framework {[Fe(2,2'-bipyridine)(CN)4]2Co(4,4'-bipyridine)}·4H2O (Fe2Co-MOF) with single-chain magnetism undergoes an intermetallic charge transfer that converts the Fe2Co charge/spin configurations from Fe(3+)LS-Co(2+)HS-Fe(3+)LS to Fe(2+)LS-Co(3+)LS-Fe(3+)LS (LS = low spin, HS = high spin) around 220 K under ambient pressure. A series of coherent phase transitions in structure, magnetism, permittivity and ferroelectricity are found to take place accompanying with the charge transfer, making Fe2Co-MOF a unique ferroelectric single-chain magnet at low temperature. Moreover, our detailed measurements of magnetization, dielectric constant, and Raman scattering under high pressures illustrate that the charge transfer as well as the resulting multifunctional transitions can be readily induced to occur at room temperature by applying a tiny external pressure of about 0.