Structural study of pressure-induced magnetic phase transitions in manganites La0.67Ca0.33MnO3 and Pr0.7Ca0.3MnO3

Abstract A crystal and magnetic structure of manganites La 0.67 Ca 0.33 MnO 3 and Pr 0.7 Ca 0.3 MnO 3 has been studied by means of powder neutron diffraction at pressures up to 5 GPa in the temperature range 15–300 K. Under high pressure, an appearance of A-type antiferromagnetic state in both systems was observed. Both compounds exhibit anisotropic compression of the lattice which leads to the apical compression of MnO 6 octahedra. Calculated from obtained structural data, pressure dependence of the charge-carrier bandwidth is in a qualitative agreement with observed pressure behavior of insulator–metal transition temperature within the framework of the double-exchange model.