Orthorhombic kagome cobaltite CaBaCo4O7: A new ferrimagnet with a of 70 K

A novel mixed valent cobaltite CaBaCo4O7 has been synthesized. Its structure, closely related to the LnBaCo4O7 oxides of the “114” series, differs from the latter by a large orthorhombic distortion, involving a buckling of the CoO4 tetrahedra of the kagome layers. Importantly, this new phase is ferrimagnetic with a TC=70 K and a very large coercive field of 2 T at 5 K, in contrast to LnBaCo4O7 oxides, which exhibit magnetic frustration.