8 research outputs found
Neutron powder diffraction study on the iron-based nitride superconductor ThFeAsN
We report neutron diffraction and transport results on the newly discovered
superconducting nitride ThFeAsN with 30 K. No magnetic transition, but a
weak structural distortion around 160 K, is observed cooling from 300 K to 6 K.
Analysis on the resistivity, Hall transport and crystal structure suggests this
material behaves as an electron optimally doped pnictide superconductors due to
extra electrons from nitrogen deficiency or oxygen occupancy at the nitrogen
site, which together with the low arsenic height may enhance the electron
itinerancy and reduce the electron correlations, thus suppress the static
magnetic order.Comment: 4 pages, 4 figures, Accepted by EP
Tracking the nematicity in cuprate superconductors: a resistivity study under uniaxial pressure
Overshadowing the superconducting dome in hole-doped cuprates, the pseudogap
state is still one of the mysteries that no consensus can be achieved. It has
been suggested that the rotational symmetry is broken in this state and may
result in a nematic phase transition, whose temperature seems to coincide with
the onset temperature of the pseudogap state around optimal doping level,
raising the question whether the pseudogap results from the establishment of
the nematic order. Here we report results of resistivity measurements under
uniaxial pressure on several hole-doped cuprates, where the normalized slope of
the elastoresistivity can be obtained as illustrated in iron-based
superconductors. The temperature dependence of along particular lattice
axis exhibits kink feature at and shows Curie-Weiss-like behavior above
it, which may suggest a spontaneous nematic transition. While seems to
be the same as around the optimal doping and in the overdoped region,
they become very different in underdoped LaSrCuO. Our results
suggest that the nematic order, if indeed existing, is an electronic phase
within the pseudogap state.Comment: 6 pages, 4 figure