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

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. High-spin Fe 3+ ion imbedded in the extended solid displays field-induced slow relaxation of magnetization with enhanced relaxation time values.