Bioinspired Citrate–Apatite Nanocrystals Doped with Divalent Transition Metal Ions

Bioinspired citrate–carbonate–apatite (cAp) nanocrystals doped with divalent transition metal (M) ions, i.e., Mn2+, Co2+, and Ni2+, were prepared by batch thermal decomplexing of Ca2+/M/citrate/phosphate/carbonate solutions at 80 and 37 °C, with initial Ca2+/M molar ratios of 9:1 and 5:5, and at different crystallization times ranging from 1 to 96 h. A thorough chemical, crystallographic, and morphological characterization was carried out on the...