September 22, 2016 12:44 PM

A phase transition with an abrupt volume collapse of >20% could be associated with dramatic changes of electronic orbitals and/or spin-states of involved transition metals. Using HPCAT capabilities of high-pressure X-ray diffraction and X-ray emission spectroscopy, the mechanism of the pressure-driven lattice collapse in MnS and MnSe is studied. More...

September 9, 2016 03:03 PM

Electronic topological transition (ETT), where new features occur in the topology of the Fermi surface, has strong influences on structural, mechanical, and electronic properties of materials. Recent nuclear resonant inelastic x-ray scattering experiments at HPCAT strongly support a thermally driven ETT that drives anomalous changes in phonon dynamics.  More...

September 9, 2016 02:53 PM

A hallmark of the iron-based superconductors is the strong coupling between magnetic, structural and electronic degrees of freedom. Using HPCAT capabilities of high-pressure x-ray diffraction and time-domain Mössbauer spectroscopy, the nematicity and magnetism in FeSe under applied pressure are found to be strongly coupled. More....

August 17, 2016 12:13 PM

Perovskite solar cells (PSCs) have attracted much attention owing to their high power conversion efficiency and low manufacturing cost. Recently, organotin perovskites have been synthesized as lead-free alternatives, and a number of chemical and processing modifications have been applied to these compounds in an effort to tune their crystal structure and electronic properties. More...

August 4, 2016 11:53 AM

Molybdenum disulfide (MoS2) attracts extensive interests because of its peculiar bandgap properties and the two-dimensional structure. The layer-dependent band structure has been studied by many theoretical calculations, including its evolution with pressure, e.g., the increase of the direct band gap by applying pressures. A recent study conducted at HPCAT reveals a structural characteristic that is strongly correlated to bandgap behavior, regardless of its form as monolayer or bulk.  More...