A cobaltite with a room temperature electrical and magnetic transition: YBaCo4O7

Short-range magnetic ordering in the geometrically frustrated layered compound YBaCo4O7 with an extended Kagomé structure

“…A room temperature hexagonal crystal structure with P6 3 mc space group was reported by several groups [1-3, 5, 15-17]. On the other hand, a trigonal crystal structure (space group P31c) with a first order phase transition to an orthorhombic crystal structure (space group Pbn2 1 ) at lower temperature (T ≤ 313 K) was also reported [4,18]. Form magnetic study, the presence of a broad magnetic peak in the powder neutron diffraction pattern, corresponding to a short-range spin-spin correlation length of 4.2 -4.6 Å, at 10 K, was reported by Valldor et al [1].…”

Layered perovskite Y1−Ca BaCo4O7+ as ceramic membranes for oxygen separation

“…Based on TGA technology, the oxygen absorption properties of RBaCo 4 O 7+ı have been investigated by several groups [20][21][22][23]. In this work, we used the O 2 -TPD technique to further investigate the oxygen desorption properties of such oxides.…”

“…Recently, a group of cobalt-rich oxides with formula RBaCo 4 O 7+ı (R = rare earth or yttrium) has captured the interest of many researchers due to their unique magnetic and electrochemical properties [17][18][19][20][21][22][23]. RBaCo 4 O 7+ı has a crystal structure similar to that of hexagonal LuBaAlZnO 7 with more details shown in Fig.…”

Magnetoelectric effect and magnetic phase diagram of a polar ferrimagnetCaBaFe4O7

“…This scenario is supported by the different temperature evolution of Co-O bond lengths at different Co sites [32]. In its sister compounds with hexagonal symmetrysuch as YbBaCo 4 O 7 , Ca 0.5 Y 0.5 BaCo 4 O 7 , and YBaFe 4 O 7 -the strong geometrical frustration fully suppresses the long-range magnetic order, and the compounds exhibit spin-glass or spin-liquid like ground states [28,[34][35][36][37][38][39]. The complex and subtle nature of the magnetic state in these materials is well exemplified by the case of YBaCo 4 O 7 , which shows no long-range magnetic order, though its orthorhombic distortion should reduce the geometrical frustration of magnetic interactions [40][41][42].…”