Single-ion and single-chain magnetism in triangular spin-chain oxides
Résumé
Sr4−xCaxMn2CoO9 oxides (x=0 and x=2) are found to exhibit magnetic responses typical of single-chain magnets (SCMs) and single-ion magnets (SIMs), two features generally investigated in coordination polymers or complexes. The compound x=0 appears to be a genuine SCM, in that blocking effects associated with slow spin dynamics yield remanence and coercivity in the absence of long-range ordering (LRO). In addition, SIM signatures of nearly identical nature are detected in both compounds, coexisting with SCM in x=0 and with LRO in x=2. It is also observed that a SCM response can be recovered in x=2 after application of magnetic field. These results suggest that purely inorganic systems could play a valuable role in the topical issue of the interplay among SIM, SCM, and LRO phenomena in low-dimensional magnetism.