G. Kopitsa et al., THE OBSERVATION OF THE MAGNETIC CORRELATIONS IN YBA2(CU1-XFEX)(3)O7-ANGLE POLARIZED NEUTRON-SCATTERING(Y CERAMICS BY SMALL), Physica. B, Condensed matter, 234, 1997, pp. 839-840
The small-angle polarized neutron scattering (SAPNS) technique has bee
n used to observe the magnetic ordering in the system of YBa2Cu2.61Fe0
.39O7+y ceramics. The anomalies of the temperature dependences of the
scattering intensity I(T, q), the polarization P(T, q) and the differe
nce Delta(T, q) in SAPNS intensities of neutrons polarized along with
or opposite to the applied magnetic field were found in the temperatur
e region T < 40 K. These effects are interpreted as scattering of neut
rons from magnetic fluctuations with characteristic scale lying in the
range from 70 to 370 Angstrom.