Related papers: First Principles Study of CaFe2As2 "Collapse" Unde…
We report the effects of hydrostatic pressure on the temperature-induced phase transitions in Fe1.08Te in the pressure range 0-3 GPa using synchrotron powder x-ray diffraction (XRD). The results reveal a plethora of phase transitions. At…
The structural properties of EuCo2As2 have been studied up to 35 GPa, through the use of x-ray diffraction in a diamond anvil cell at a synchrotron source. At ambient conditions, EuCo2As2 (I4/mmm) has a tetragonal lattice structure with a…
We measured the electrical resistivity and ac magnetic susceptibility of BaFe2As2 and SrFe2As2 single crystals under pressure using a cubic anvil apparatus. For BaFe2As2, the antiferromagnetic (AF) and structural transitions are suppressed…
Neutron diffraction measurements of a high quality single crystal of CaFe2As2 are reported. A sharp transition was observed between the high temperature tetragonal and low temperature orthorhombic structures at TS = 172.5K (on cooling) and…
By performing pressure simulations within density functional theory for the family of iron-based superconductors $Ae{}A$Fe$_4$As$_4$ with $Ae$ = Ca, Sr, Ba and $A$ = K, Rb, Cs we predict in these systems the appearance of two consecutive…
The surprising discovery of tripling the superconducting critical temperature of KFe$_2$As$_2$ at high pressures issued an intriguing question of how the superconductivity in the collapsed tetragonal phase differs from that in the…
The pressure dependence of a large number of phonon modes in CaFe2As2 with energies covering the full range of the phonon spectrum has been studied using inelastic x-ray and neutron scattering. The observed phonon frequency changes are in…
The recent discovery and subsequent developments of FeAs-based superconductors have presented novel challenges and opportunities in the quest for superconducting mechanisms in correlated-electron systems. Central issues of ongoing studies…
We report the temperature-pressure phase diagram of CaKFe$_4$As$_4$ established using high pressure electrical resistivity, magnetization and high energy x-ray diffraction measurements up to 6 GPa. With increasing pressure, both resistivity…
In contrast to the simultaneous structural and magnetic first order phase transition $T_{0}$ previously reported, our detailed investigation on an underdoped Ba$_{0.84}$K$_{0.16}$Fe$_{2}$As$_{2}$ single crystal unambiguously revealed that…
Intrinsic, in-plane anisotropy of electrical resistivity was studied on mechanically detwinned single crystals of SrFe$_2$As$_2$ above and below the temperature of the coupled structural/magnetic transition, $T_{\textrm{TO}}$. Resistivity…
Iron-pnictides Ca(Fe1-xRhx)2As2 (x = 0, 0.035, and 0.19) were studied across the tetragonal-orthorhombic and uncollapsed to collapsed tetragonal phase transitions using Raman spectroscopy. The effect of the phase separation was observed in…
Superconductivity under pressure in FeSe ($T_{\rm c}$$\sim$7.5 K) has been investigated using single-crystal specimens through the measurements of DC magnetization and electrical resistivity. A characteristic three-step increase in $T_{\rm…
In CaFe2As2, superconductivity can be achieved by applying a modest c-axis pressure of several kbar. Here we use scanning tunneling microscopy/spectroscopy (STM/S) to explore the STM tip pressure effect on single crystals of CaFe2As2. When…
Cadmium arsenide Cd$_3$As$_2$ hosts massless Dirac electrons in its ambient-conditions tetragonal phase. We report X-ray diffraction and electrical resistivity measurements of Cd$_3$As$_2$ upon cycling pressure beyond the critical pressure…
1T-TaS$_2$ is a prototypical charge-density-wave (CDW) system with a Mott insulating ground state. Usually, a Mott insulator is accompanied by an antiferromagnetic state. However, the antiferromagnetic order had never been observed in…
The effects of pressure generated in a liquid medium, clamp, pressure cell on the in-plane and c-axis resistance, temperature-dependent Hall coefficient and low temperature, magnetoresistance in CaFe2As2 are presented. The T - P phase…
Compounds with a tetragonal ThCr$_{2}$Si$_{2}$-type structure are characterized by the possibility of the isostructural phase transition from the tetragonal phase to the collapsed tetragonal phase induced by the external pressure. An…
The magnetism of the second antiferromagnetic phase (AF2) arising in the iron-based LaFeAsO$_{1-x}$H$_{x}$ superconductor for $x\gtrsim0.4$ was investigated by muon spin rotation measurements under hydrostatic pressure up to 2.6 GPa. The…
We report the structure and magnetism of PrOFeAs, one of the parent phases of the newly discovered Fe-As superconductors, as measured by neutron powder diffraction. In common with other REOFeAs materials, a tetragonal-orthorhombic phase…