Formation of a single-ion magnet in the lanthanum calcium silicate apatite structure by the cobalt oxide doping

A small amount of cobalt was incorporated into the lanthanum calcium silicate apatite structure by annealing at 1500 °C in argon. The compound exhibits easy-axis magnetic anisotropy with a zero-field splitting parameter 2D of −60 cm⁻¹ and field- induced slow relaxation of magnetization with a remagnetization energy barrier of 58–63 cm⁻¹. Thereby, for the first time, a cobalt-based single-ion magnet was created in silicate.