63,974 research outputs found
Muon-spin rotation and magnetization studies of chemical and hydrostatic pressure effects in EuFe_{2}(As_{1-x}P_{x})_{2}
The magnetic phase diagram of EuFe(AsP) was
investigated by means of magnetization and muon-spin rotation studies as a
function of chemical (isovalent substitution of As by P) and hydrostatic
pressure. The magnetic phase diagrams of the magnetic ordering of the Eu and Fe
spins with respect to P content and hydrostatic pressure are determined and
discussed. The present investigations reveal that the magnetic coupling between
the Eu and the Fe sublattices strongly depends on chemical and hydrostatic
pressure. It is found that chemical and hydrostatic pressure have a similar
effect on the Eu and Fe magnetic order.Comment: 11 pages, 10 figure
First principles investigation of topological phase in XMR material TmSb under hydrostatic pressure
In this article, we report emergence of topological phase in XMR material
TmSb under hydrostatic pressure using first principles calculations. We find
that TmSb, a topologically trivial semimetal, undergoes a topological phase
transition with band inversion at X point without breaking any symmetry under a
hydrostatic pressure of 12 GPa. At 15 GPa, it again becomes topologically
trivial with band inversion at as well as X point. We find that the
pressures corresponding to the topological phase transitions are far below the
pressure corresponding to structural phase transition at 25.5 GPa. The
reentrant behaviour of topological quantum phase with hydrostatic pressure
would help in finding a correlation between topology and XMR effect through
experiments.Comment: 12 pages, 4 figure
Pressure and temperature driven phase transitions in HgTe quantum wells
We present theoretical investigations of pressure and temperature driven
phase transitions in HgTe quantum wells grown on CdTe buffer. Using the 8-band
\textbf{kp} Hamiltonian we calculate evolution of energy band structure
at different quantum well width with hydrostatic pressure up to 20 kBar and
temperature ranging up 300 K. In particular, we show that in addition to
temperature, tuning of hydrostatic pressure allows to drive transitions between
semimetal, band insulator and topological insulator phases. Our realistic band
structure calculations reveal that the band inversion under hydrostatic
pressure and temperature may be accompanied by non-local overlapping between
conduction and valence bands. The pressure and temperature phase diagrams are
presented.Comment: 9 pages, 8 figures + Supplemental material (5 pages
Suppression of the magnetic order in CeFeAsO: non-equivalence of hydrostatic and chemical pressure
We present a detailed investigation of the electronic properties of CeFeAsO
under chemical (As by P substitution) and hydrostatic pressure by means of
in-house and synchrotron M\"ossbauer spectroscopy. The Fe magnetism is
suppressed due to both pressures and no magnetic order was observed above a
P-substitution level of 40% or 5.2 GPa hydrostatic pressure. We compared both
pressures and found that the isovalent As by P substitution change the
crystallographic and electronic properties differently than hydrostatic
pressure.Comment: supplement is included in the pdf fil
Neutron scattering study of a quasi-2D spin-1/2 dimer system Piperazinium Hexachlorodicuprate under hydrostatic pressure
We report inelastic neutron scattering study of a quasi-two-dimensional S=1/2
dimer system Piperazinium Hexachlorodicuprate under hydrostatic pressure. The
spin gap {\Delta} becomes softened with the increase of the hydrostatic
pressure up to P= 9.0 kbar. The observed threefold degenerate triplet
excitation at P= 6.0 kbar is consistent with the theoretical prediction and the
bandwidth of the dispersion relation is unaffected within the experimental
uncertainty. At P= 9.0 kbar the spin gap is reduced to 0.55 meV from 1.0 meV at
ambient pressure.Comment: 4 pages, 5 figure
Pressure Effect on the superconducting properties of LaO_{1-x}F_{x}FeAs(x=0.11) superconductor
Diamagnetic susceptibility measurements under high hydrostatic pressure (up
to 1.03 GPa) were carried out on the newly discovered Fe-based superconductor
LaO_{1-x}F_{x}FeAs(x=0.11). The transition temperature T_c, defined as the
point at the maximum slope of superconducting transition, was enhanced almost
linearly by hydrostatic pressure, yielding a dT_c/dP of about 1.2 K/GPa.
Differential diamagnetic susceptibility curves indicate that the underlying
superconducting state is complicated. It is suggested that pressure plays an
important role on pushing low T_c superconducting phase toward the main
(optimal) superconducting phase.Comment: 7 pages, 4 figure
Unique phase diagram with narrow superconducting dome in EuFe(AsP) due to Eu local magnetic moments
The interplay between superconductivity and Eu magnetic moments in
EuFe(AsP) is studied by electrical resistivity measurements
under hydrostatic pressure on and single crystals. We can map
hydrostatic pressure to chemical pressure and show, that superconductivity
is confined to a very narrow range in the phase diagram,
beyond which ferromagnetic (FM) Eu ordering suppresses superconductivity. The
change from antiferro- to FM Eu ordering at the latter concentration coincides
with a Lifshitz transition and the complete depression of iron magnetic order.Comment: 4 page
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