Magnetic states and the crystal volume of Nd2/3Ca1/3MnO3: analysis of phase transformations

The neutron diffraction and magnetic studies of the Nd2/3Ca1/3MnO3 ceramic compound have been carried out aiming to reveal the signs of phase separation in the system. A well-expressed step in the inverse magnetic susceptibility of the system found at T∼212K was considered to be a result of the charge ordering. The elastic neutron scattering study upon heating has shown a diminishing to zero of intensities of the diffraction peaks, corresponding to the ferromagnetic B-type structure, antiferromagnetic DE-type and pseudo-CE-type structures at ∼70 and ∼80 K by the first order phase transitions, and at ∼130 K by the second order transition, respectively. We suppose that the set of the revealed magnetic structures relates to the set of structure regions formed due to the nucleation of the martensitic particles within the parent matrix below the charge ordering temperature.