La0.7Ca0.3Mn0.95M0.05O3 manganites (M=Al, Ga, Fe, Mn, and In): Local structure and electron configuration effect on Curie temperature and magnetization

Abstract: X-ray diffraction and magnetization measurements have been carried out in manganites (, Ga, Fe, Mn, and In). It was found that the samples belong to orthorhombic phase and lattice parameters increase with increasing ionic radius of the dopants. Curie temperature, , changes with doping due to a difference between the electron configuration (E-factor) and ionic radius (S-factor) of the dopants and manganese trivalent ion. The E-factor affects the stronger than the S-factor and causes the decrease. The S-factor can cause both positive and negative change in . The change, caused by the S-factor, is positive if ionic radius of the dopant is less than that of ion, and negative in opposite case, if dopant ionic radius is larger than that of ion. Saturation magnetization of the manganites decreases continuously with increasing ionic radius of the substituents and almost independent of magnetic nature of the dopants. [Copyright &y& Elsevier]