Gadolinium ion bonding on the surface of carboxylated detonation nanodiamond in terms of magnetochemistry and density functional theory

Gadolinium ions (Gd³⁺) can be fixed on the surface of 5-nm detonation nanodiamonds with terminal carboxyl and/or hydroxyl surface groups. Magnetization curves measured below the temperature of liquid helium at normal pressure give the amount of Gd³⁺ ions of about 18 per a 5-nm nanodiamond particle. The corresponding 2D surface density of ions is smaller than that obtained by density functional theory for a single gadolinium atom fixed on the surface of (111) diamond slab with 36 surface carbon sites with up-standing s-bonds by a factor of 2.