The LDA and LDA + U calculated total and local magnetic moments of several sites for Mn0.25Ca0.75S, Mn0.5Ca0.5S and Mn0.75Ca0.25S in the ferromagnetic state are given in Table 4. Our results show that
Daunorubicin HCl the total magnetic moment per Mn of rock-salt MnxCa1−xS is 4.4μB and 4.5μB for LDA and LDA + U and is independent of the Mn concentration. Permanent local magnetic moments are produced from the nonmagnetic Ca and S sites, whose magnetic moments are antiparallel to the Mn moment. This may be understood as the tunneling of spin-up impurity states into the neighboring atoms. The hybridization between S-3p and Mn-3d states is responsible on the local magnetic moment on the nonmagnetic sites. The unfilled Mn-3d levels reduce the local magnetic moment of Mn from its free space charge value of 5μB[30] to 4.4 μB and 4.54 μB for LDA and LDA + U due to 3p–3d hybridization. These values are closer to experimental one 4.54 μB and the theoretical data 4.6 μB reported by R. Tappero and A. Lichanot using the DFT method corrected by a local (L-PZ) or by a gradient (B-LYP) potential model [19]. The hybridization between Ca–p, S-p states and Mn-3d states reduces the total magnetic moment and produces small local magnetic moment on the non-magnetic Ca and S sites. The magnetism is seen in shrinkage of the interatomic distances in the FM spin-ordered. The lowest
energy FM has lower average Mn–Mn distances. Total and induced magnetic moments on the nonmagnetic Ca and S sites increase with increasing elastic constants and when the material becomes less compressible.
