Neutron investigation of Tb1-xCaxMnO3 (x ≥ 0.5)

Crystal and magnetic structures of Tb1-xCaxMnO3 (x greater than or equal to 0.5) have been investigated by means of neutron powder diffraction experiments. We have derived the magnetic phase diagram against hole concentration x and temperature T: the spin structure changes as CE- --> C- --> G-type structure with increase of x. In the vicinity of the magnetic phase boundaries, magnetically phase separated state has been observed. At high temperature region, we observe the metallic behavior in a wide x region (0.70 less than or equal to x less than or equal to 0.95), and ascribe it to the enhanced one-electron bandwidth TV of the, epsilon (g) state.