Slow magnetization relaxation of a high-spin iron(iii) in mayenite Ca12Al14O33

Abstract

Samples of the Fe(III) doped calcium aluminate with an anti-zeolite type structure were prepared. The crystal structure parameters were determined, and dc and ac magnetic properties were studied. It is found that Fe(III) partially substitutes for Al(III) at a trigonally distorted tetrahedral site. This results in the occurrence of easy-axis magnetic anisotropy and field-induced slow relaxation of magnetization. This is the first example of a high-spin Fe(III) single ion magnet in all-inorganic solid, which, in addition, features higher magnetization relaxation times at elevated temperatures than any known Fe(III) coordination compound.