Chemical pressure effect on the magnetic order of the La1.4Sr1.6Mn2O7 bilayered manganite

In this paper we have studied, by means of high-resolution neutron powder diffraction, the structural and magnetic feature of pure La1.4Sr1.6Mn2O7 and Sr-doped (25%) La1.4Sr1.6Mn2O7.Our data reveal the stabilization of the A-type AFM long-range order for the La1.4Sr1.6Mn2O7 bilayered manganites induced by the partial replacement of the Sr with the smaller Ca, keeping constant the hole doping. This can be in turn due to the change in the orbital character of the eg electrons as a function of Ca-doping.