Observation of a large magnetic anisotropy in the new 2H-Perovskite related oxide Ba8CoRh6O21: Magnetic measurements on aligned single crystals

Single crystals of Ba8CoRh6O21, grown out of a potassium carbonate flux, we re characterized by single-crystal X-ray diffraction and magnetic measureme nts. X-ray data were collected in a superspace group approach and solved us ing the JANA2000 software package. Ba8CoRh6O21 represents the first example of a structurally characterized m = 5, n = 3 member of the A(3n+3m)A ' nB3 m+nO9m+6n family of 2H hexagonal perovskite related oxides and contains cha ins consisting of six consecutive RhO6 octahedra followed by one distorted CoO6 trigonal prism. Magnetic measurements were carried out on large aligne d single crystals, and a very large magnetic anisotropy in the magnetic sus ceptibility, persisting up to room temperature, was observed.