Hyperfine magnetic fields at the nuclei of probe <sup>119</sup>Sn atoms and exchange interactions in the CaCu<sub>3</sub>Mn<sub>3.96</sub>Sn<sub>0.04</sub>O<sub>12</sub> manganite
We have investigated the hyperfine magnetic interactions between the nuclei of probe 119Sn atoms in the CaCu3Mn3.96Sn0.04O12 double manganite by Mössbauer spectroscopy using magnetic measurements. A consistent description of the results obtained in terms of the Weiss molecular field model by taking into account the peculiarities of the local environment of tin atoms has allowed the indirect Cu2+-O-Mn4+ (J CuMn ≈ −51 ± 1 K) and Mn4+-O-Mn4+ (J MnMn ≈ −0.6 ± 0.6 K) exchange interaction integrals to be estimated. Based on the Kanamori-Goodenough-Anderson model, we show that the magnitude and sign of the intrasublattice exchange integral J MnMn correspond to both the electronic configuration of the Mn4+ cations and the geometry of their local crystallographic environment in the compound under study
