From ferrimagnetism to spin-glass behavior in alkali- and rare-earth metal crichtonites

In this work, nine new synthetic alkali- and rare-earth metal crichtonite-type compounds with AB 3 C 18 O 38 general formula are presented. The effect on the magnetic properties as consequence of the substitution of divalent and trivalent cations in the A site, as well as the introduction of iron at the B and C sites is studied. Ferrimagnetic behavior was identified in the crichtonites CaMn 3 Ti 18 O 38 , BaMn 3 Ti 18 O 38 and CaFe 3 Ti 18 O 38 , which changes to a spin-glass type for the BaMn 3 Ti 14 Fe 4 O 38 and A -trivalent REMn 3 Ti 18 O 38 (RE = La, Ce and Nd), LaFe 3 Ti 18 O 38 and LaMn 3 Ti 13 Fe 5 O 38 . A comprehensive comparison of the AC and DC magnetic measurements for whole series along with the FiM structure obtained by neutron powder diffraction is discussed. These results will expand the comprehension on this almost unexplored magnetic family of compounds. Nine compounds belonging to the crichtonite-type of minerals (AB 3 C 18 O 38 ) demonstrate the potentiality of this structure as a new magnetic playground with ferrimagnetic and spin-glass behaviour. • Nine new crichtonites are reported. • Ferromagnetic to spin-glass behaviour is observed. • Properties, magnetic and crystal structures are reported.