Ferromagnetism in Ba5Co5O14:: A structural, transport, thermal, and magnetic study -: art. no. 144402

The crystal and magnetic structure of Ba5Co5O14 has been determined by means of x-ray and neutron diffraction. This oxide has trigonal symmetry (space group P-3m1) and lattice parameters a=5.6453(3) angstrom and c=11.9223(7) A. The main structural feature is the presence of blocks of composition Co3O12, folded along c axis, built up by units of three sharing-faces octahedra connected through their terminal corners to two CoO4 tetrahedra, which define layers parallel to the basal plane (001). The material shows ferromagnetic behavior with T-C approximate to 47 K. As determined from neutron diffraction data, the magnetic moments are aligned parallel lying on the (101) plane (and equivalent), making an angle of 63 degrees with the c axis. The Curie temperature (T-C) strongly increases with the hydrostatic pressure (1.1 K/GPa) until 6 GPa, and it decreases for higher pressures. From the electronic point of view, Ba5Co5O14 is a low-dimensional system with an Anderson localization state of the charge carriers.