Related papers: First-principles study of lithium-doped carbon cla…
The use of high pressure to realize superconductivity in the vicinity of room temperature has a long history, much of it focused on achieving this in hydrogen rich materials. This paper provides a brief overview of the work presented at…
Crystal structures of $\textrm{CLi}_4$ compounds are explored through \emph{ab} \emph{initio} evolutionary methodology. Phase transition from metal to semimetal and semiconductor, and eventually to insulator with increasing pressure are…
Electrides are materials in which some of the electrons are localized at the interstitial sites rather than around the atoms or along atomic bonds. Most elemental electrides are either alkali metals or alkaline-earth metals because of their…
Pressure-induced superconductivity and structural phase transitions in phosphorous (P) are studied by resistivity measurements under pressures up to 170 GPa and fully $ab-initio$ crystal structure and superconductivity calculations up to…
Room-temperature superconductivity was recently discovered in carbonaceous sulfur hydride (C-S-H) close to 3\,Mbar. We report significant differences in the superconducting response of C-S-H, with a maximum $T_{C}$ of 191(1)\,K, below a…
Almost identical thermal properties of type-I clathrate compounds to those of glasses follow naturally from the consideration that off-centered guest ions possess electric dipole moments. Local fields from neighbor dipoles create many…
Gas hydrates are potential candidates in future energy sources while simultaneously providing structures with extensive applications in carbon capture and storage, gas transport, and important separation processes. Prior research in the…
We investigate the superconductivity of carbon compounds with a sodalite structure, which are similar to hydrogen compounds showing the high-temperature superconductivity. A systematic analysis by first-principles calculations is carried…
The layered structure of tetragonal Ni(CN)2, consisting of square-planar Ni(CN)4 units linked in the a-b plane, with no true periodicity along the c-axis, is expected to show anisotropic compression on the application of pressure.…
CrAs was firstly observed possessing the bulk superconductivity (Tc~2 K) under high pressure (0.8 GPa) in the very recent work (Wei Wu, et al. Nature Communications 5, 5508 (2014)). To explore the correlation between the structure and the…
First thermoelectric properties measurements on bulk nanostructured Ba8Ga16Ge30 clathrate-I are presented. A sol-gel-calcination route was developed for preparing amorphous nanosized precursor oxides. The further reduction of the oxides led…
Clathrates are a class of inclusion compounds that offer various useful and surprising phenomena, including superconductivity, thermoelectricity, and the potential for high-density ion storage. Stability conditions within the…
Elements of group I in the Periodic table have valence electrons of s-type and are usually considered as simple metals. Crystal structures of these elements at ambient pressure are close-packed and high-symmetry of bcc and fcc types,…
Crystalline solids are generally known as excellent heat conductors, amorphous materials or glasses as thermal insulators. It has thus come as a surprise that certain crystal structures defy this paradigm. A prominent example are type-I…
Pressure can tune material's electronic properties and control its quantum state, making some systems present disconnected superconducting region as observed in iron chalcogenides and heavy fermion CeCu2Si2. For CaC6 superconductor (Tc of…
The behaviour of partially ionized hot compressed matter is critical to the study of planetary interiors as well as for nuclear fusion studies. A recent quantum study of carbon in the 10-70 Gbar range and at a temperature of 100 eV used…
This work presents an in-depth investigation of the properties of complexes composed of hydrogen, silicon or oxygen with carbon, which are major unintentional impurities in undoped GaN. This manuscript is a complement to our previous work…
Hydrogen-rich superhydrides are believed to be very promising high-Tc superconductors as they are expected to mimic characteristics of metallic hydrogen. Recent experiments discovered superhydrides at very high pressures, e.g. FeH5 at 130…
We report a room-temperature optical reflectivity study performed on [112]-oriented Cd$_3$As$_2$ single crystals over a broad energy range under external pressure up to 10 GPa. The abrupt drop of the band dispersion parameter…
Electronic structures of carbides with the rocksalt structure were calculated by full potential electronic codes solving the Kohn-Sham equation. Bonding characters were analyzed by constructing tight-binding Hamiltonian based on…