OCTOBER 2, 2019 — Hydrogen-rich superhydrides are very promising candidates to achieve superconductivity close to room temperature. Most of the superhydrides stabilize at very high pressures. A team of scientist led by Dr. Nilesh P. Salke at the Center for High Pressure Science and Technology Advanced Research (HPSTAR) has discovered the cerium superhydride CeH9 at 80-100 GPa with laser heating....
New work from a team led by HPSTAR’s Dr. Mingqiang Hou confirmed that aragonite — a high-pressure mineral form of CaCO3, will turn to a stable amorphous phase at the subduction zone conditions. This study proposed that the amorphous calcium carbonate may help cycle carbon to the surface. Their findings are published in recent Nature Communications.
OCTOBER 7, 2019 — New study from a team of scientists led by Dr. Xiaojia Chen from HPSTAR found that pressure can improve the ability of materials to turn heat into electricity and could potentially be used to create clean generators. The work is published in Nature Materials.
SEPTEMBER 26, 2019 — An international team led by HPSTAR director Dr. Ho-Kwang Mao succeeded in determining how hydrogen molecules are packed at extremely high pressures. Their work solved the long-standing mystery of what is the structure of the dense form of hydrogen, called phase IV (Roman numeral four). This work is published in Nature.
AUGUST 15, 2019 — New study from a team of scientists led by Dr. Lin Wang of HPSTAR find pressure can effectively tune the photoreponses of nano heterojunction. They found a reversible inverse photoconductivity transition in WO3/CuO heterostructure under high pressure. Their study may provide an applicable tool with enhanced performance for photovoltaic devices, functioning as a switch, controller...
JUNE 20, 2019 — New study from a team of scientists led by Dr. Lin Wang of HPSTAR applied high pressure to tune the physical properties of 2D hybride perovskite (C4H9NH3)2PbI4. They found that pressure can tremendously improve the performace of 2D perovskite — the band gap is narrowed by~54% and the carrier lifetime is 20 times longer for (C4H9NH3)2PbI4 (BA2PbI4) compared to the value at ambient ...
JULY 22, 2019 — Extra capacity can be achieved by the redox of oxygen anions in addition to the redox of transition metals (Li/Na rich cathodes). However, the challenges remain in Li/Na rich cathodes are the reversible oxygen redox and the voltage decay/ hysteresis. A team of scientists co-led by Dr. Mingxue Tang from HPSTAR systematically investigated the mechanism behind the highly reversible...
JULY 18, 2019 — Variant selection is classic phenomenon during the martensitic transformations that induced by temperature. In the latest issue of PNAS, a team of scientists led by Dr. Binbin Yue from HPSTAR reported a simple variant selection effect across the pressure/stress driven martensitic transformations in Mn2O3. This work is a classic model reference to demonstrate the variant selection...
JULY 2, 2019 — Sodium-sulfur (Na-S) batteries are promising candidate for solid state batteries due to their high ionic conductivity, long cycle-life, high specific energy, and low material cost. A systematic and unambiguous understanding of the charging/discharging process in batteries is of great significance for the optimization of Na-S batteries. However, the fundamental structure...
JUNE 12, 2019 — New work from a team of scientists co-led by Dr. Haiyan Zheng from HPSTAR found pressure induced tremendous modulation of the optical properties of an organic molecular crystal (DPFO). Their study shows that DPFO may have potential in the molecular switch applications of modulating photoluminescence under high pressure. Their work is published in recent Materials Chemistry...
MAY 24, 2019 — The intertwined charge, spin, orbital, and lattice degrees of freedom make the 5d compounds have exotic properties. Current interest is focused on electromagnetic interactions in these materials, whereas the important role of lattice geometry remains to be fully recognized. A group of scientists led by Dr. Yang Ding of HPSTAR, found pressure induced lattice frustration in a spin...
MAY 21, 2019 — An international team of scientists including Dr. Xujie Lü has developed a new halogen conversion–intercalation chemistry in graphite that produces composite electrodes with a capacity of 243 mAh g-1 at an average potential of 4.2 volts versus Li/Li+. The study is recently published in Nature.
APRIL 18, 2019 — New work from a team of scientists led by Dr. Hengzhong Zhang at HPSTAR probed the phase variation of natural bulk brookite under compression. They revealed how pressure medium affect the phase transition behavior of brookite. This study may be used for inferring the geological fate of brookite in nature. The work is published in ACS Earth and Space Chemistry.
APRIL 20, 2019 — A team of scientists led by Dr. Feng Ke of HPSTAR observed the semiconducting character in compressed trilayer graphene through in-situ electrical measurements. An intrinsic bandgap of ~2.5 eV has been achieved. The realization of such wide bandgap in graphene opens new opportunities in carbon-based electronic devices. Their study was published in the recent issue of PNAS.
APRIL 23, 2019 — Scientists from HPSTAR and The University of Hong Kong combined in situ synchrotron x-ray diffraction and density functional theory and evolutionary algorithms to probe the possible new compounds in Pb-Te system. The team discovered a new cation-rich compound, Pb3Te2 in the binary system. This work is published in recent ACS Central Science.
APRIL 17, 2019 — Sulfide-based superionic conductors with high ionic conductivity have been explored as a promising candidate for solid-state Li batteries. However, their hypersensitive nature against moisture has not only made their manufacturing process complicated and costly, but also impeded their applications in novel batteries including the aqueous Li-air and Li-redox-flow designs. A sulfide...
MARCH 28, 2019 — New study from an international research team of scientists co-authored by Dr. Kuo Li from HPSTAR found that a class of disordered materials, called plastic crystals, exhibit record-large barocaloric effects under very weak pressure. The study reveals that the plastic crystals are the most promising materials for green cooling applications. The study is published in the recent...
MARCH 18, 2019 — New study from a team of scientists led by Dr. Lin Wang of HPSTAR investigated the stoichiometry and structural evolutions of phosphine (PH3) under high pressures. They found that PH3 molecules went through a step-by-step polymerization and finally dissociated to elemental phosphorus and hydrogen instead of directly dissociation as previously reported. Low temperature was found...
MARCH 13, 2019 — A new comprehensive study led by Dr. Gang Liu, a staff scientist at HPSTAR, reviewed the manipulation, modification, and improvement of photovoltaic perovskite materials by pressure engineering. The study focuses on the unique overlapping region between Green energy, materials, and engineering and explores whether desirable characteristics for next-generation materials-by-design ...
MARCH 14, 2019 — Due to the realization of potentially exotic states, the behaviour of elemental molecular systems at high densities has long been of particular interest in the condensed matter sciences. Of the 7 elemental diatomic systems, only O2 and the heavier halogens Br2 and I2 have conclusively demonstrated electrically conductive properties in the condensed state, whilst the latter two are...