Electrical and magnetic phases of the layered perovskite Ca4−xLaxMn3O10

Abstract

We analyze magnetic susceptibility, resistivity and neutron diffraction measurements of the electron doped triple layered perovskite, or Ruddlesden–Popper class of manganates Ca4−xLaxMn3O10. Near the undoped region a paramagnetic insulator to antiferromagnetic insulator transition is observed with decreasing temperature and a concomitant change in the conduction process from thermal activation to Mott-type hopping. For larger doping, with a Mn valence of 3.97, there is a transition from the paramagnetic insulator to a canted antiferromagnetic insulator which exhibits a more dramatic change in the conduction mechanism.