Static magnetic order and superfluid density of RFeAs(O,F) (R=La,Nd,Ce) and LaFePO studied by muon spin relaxation: unusual similarities with the behavior of cuprate superconductors.
Muon spin relaxation measurements in iron-oxypnictide systems have revealed: (1) commensurate long-range order in undoped LaFeAsO; (2) a Bessel function line shape in LaFeAs(O0.97F0.03) which indicates possible incommensurate or stripe magnetism; (3) anomalous weak magnetism existing in superconducting LaFePO, CeFeAs(O0.084F0.16), and NdFeAs(O0.88F0.12) but absent in superconducting LaFeAs(O0.92F0.08); and (4) scaling of the superfluid density with T_{c} in the Ce-, La-, and Nd-FeAs superconductors following a nearly linear relationship found in cuprates.
Carlo
J P
JP
Department of Physics, Columbia University, New York, New York 10027, USA.
Uemura
Y J
YJ
Goko
T
T
Macdougall
G J
GJ
Rodriguez
J A
JA
Yu
W
W
Luke
G M
GM
Dai
Pengcheng
P
Shannon
N
N
Miyasaka
S
S
Suzuki
S
S
Tajima
S
S
Chen
G F
GF
Hu
W Z
WZ
Luo
J L
JL
Wang
N L
NL