2 research outputs found
La-NMR study of spin-dynamics coupled with hole mobility in *-type LaEuSrCuO
In *-type cuprate oxides with five oxygen coordination, little is known
about the relationship between the spin correlations and dope carriers. We
performed La-nuclear magnetic resonance (NMR) and electrical
resistivity measurements on an as-sintered (AS) and oxidation annealed (OA)
polycrystalline *-type LaEuSCuO (LESCO) to
investigate its magnetic and superconducting (SC) properties. Upon cooling, the
NMR spectrum of AS LESCO broadened below 3 K, at which the nuclear spin-lattice
relaxation rate against the temperature exhibited a maximum, thereby
indicating the appearance of static magnetism. The temperature dependence of
between 3 K and 20 K was similar to that of the resistivity displaying
the semiconducting behavior. Furthermore, the energy scale of the transport gap
and spin-dynamics estimated was found to be comparable. These results suggest a
close connection between the mobility of the doped carriers and low-energy
spin-dynamics, as reported for lightly doped -type LaSrCuO.
In the OA SC sample, we confirmed the absence of a magnetic order and the
Korringa relation above 10 K. Therefore, in the *-type LESCO with =
0.28, the magnetic state coupled with holes drastically turns to the weakly
correlated metallic state by oxidation annealing.Comment: 6 pages, 6 figure