Structural study of Ni-substituted YBaCo4−xNixO7 frustrated cobaltites

Thermal evolution of the diffractogram for a sample YBaCo3.9Ni0.1O7.00 collected on cooling at the LNLS synchrotron source. The Bragg reflections were indexed in the trigonal P31c and orthorhombic Pbn21 space groups above and below the transition temperature TS, indicated with an arrow. The region of coexistence of both phases is indicated as ΔT. A projection along the c-axes for both crystal structures is shown on the right.