In this paper we show that a flash lamp can be employed to induce controlled lateral solidification of a-Si thin films. Specifically, a dual xenon-arc-lamp-based system was utilized to induce location-controlled compl...
详细信息
BaIrO3 adopts the 9R polytype structure if it is synthesized at ambient pressure. High-pressure and high-temperature treatments up to 10 GPa have led to other 5H and 6H polytype phases, which are quenchable to the amb...
详细信息
BaIrO3 adopts the 9R polytype structure if it is synthesized at ambient pressure. High-pressure and high-temperature treatments up to 10 GPa have led to other 5H and 6H polytype phases, which are quenchable to the ambient condition. However, the single-phase 3C perovskite, the end member of polytypes, has not been obtained so far. Here we report the high-pressure synthesis of BaIrO3 perovskite under 25 GPa and 1150 °C. Rietveld refinement on the powder x-ray diffraction pattern revealed that this new compound crystallizes in a tetragonal I4/mcm structure rather than the expected cubic Pm-3m structure. The new perovskite is a Pauli paramagnetic metal with a Fermi liquid ground state, i.e., ρ ∝ T2 below 6 K. The availability of BaIrO3 perovskite also allows completion of the structure-physical property evolution in the AIrO3 perovskites (A = Ca, Sr, Ba). The Fermi energy located in bands originated from Ir: 5d and O: 2p electrons are found to be very sensitive to the change of crystal structure.
Positronium (Ps) is shown to exist in a delocalized state in self-assembled metalorganic crystals that have large 1.3–1.5 nm cell sizes. Belonging to a class of materials with record high accessible specific surface ...
详细信息
Positronium (Ps) is shown to exist in a delocalized state in self-assembled metalorganic crystals that have large 1.3–1.5 nm cell sizes. Belonging to a class of materials with record high accessible specific surface areas, these highly porous crystals are the first to allow direct probing with simple annihilation lifetime techniques of the transport properties of long-lived triplet Ps in what is hypothesized to be a Bloch state. Delocalized Ps has unprecedented (high) Ps mobility driven primarily by weak phonon scattering with unusual and profound consequences on how Ps probes the lattice.
There is a growing interest in Zn1-xBexO (ZBO)/ZnO heterostructures and quantum wells since the band gap energy of ZBO solid solutions can be tuned over a very large range (3.37-10.6 eV) as a function of the Be compos...
详细信息
暂无评论