Spin correlations and magnetonuclear cross-correlation in Sm(Sr)-Mn-O perovskites in the low-temperature phase

The results of measurements of spin correlations and magnetonuclear cross-correlations (MNCCs) in the system ¹⁵⁴Sm_1−x Sr_xMnO₃ with the perovskite structure (x=0.25,0.4) in the low-temperature phase in magnetic fields 0<H<1 kOe are presented. These are the first measurements performed by the small-angle polarized-neutron scattering method (SAPNS). It is shown that ferromagnetic correlations with a scale of 180–250 Å and MNCCs characterizing the intercoupling of the magnetic and lattice subsystems on this scale exist in the system. It is found that in the low-temperature phase the system exhibits spin-glass properties. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 4, 323–328 (25 February 1999)