Oleic acid and oleylamine are added in a solution containing suitable precursors and they can often form complexes with metal ions. These complexes may be thermally decomposed to yield ligand-coated nanoparticles with a tendency to form assemblies.

Ferromagnetism in 2D materials has attracted tremendous interest from the scientific community thanks to its potential for the design of magnetic materials with unique properties. The presence of a ferromagnetic element in a 2D material can improve the existing properties and offer new ones, giving rise to the development of manifold applications. This review focuses on recent advances and perspectives of 2D materials that bear at least one ferromagnetic element (iron, cobalt, nickel) as i) structural constituent, ii) dopant atom, or iii) adjacent atom through proximity effect. By describing in detail the magnetic properties that have emerged so far, their potential to form next‐generation 2D magnets is discussed. Moreover, the contribution of such 2D materials is analyzed in various applications (electrochemical, photochemical, optical, and electronic), aiming to explore further functionalities and capabilities of ferromagnetic elements, apart from their magnetic nature. Special attention is given to gadolinium and other rare earth elements that display a ferromagnetic order even at ultra‐low temperatures and form part of 2D structured materials, with particularly appealing properties deriving from their 4f electrons.

Nickel ferrite nanoparticles were synthesized via a facile solvothermal approach. Oleylamine (OAm) was used in all synthetic procedures as a stabilizing agent and solvent. By varying the polarity of the solvents, hydrophobic NiFe₂O₄ nanoparticles coated with OAm of relatively similar sizes (9–11.7 nm) and in a range of magnetization values (32.0–53.5 emu g⁻¹) were obtained. The as-prepared hydrophobic nanoparticles were characterized by XRD, TEM, SEM, TGA and VSM and converted to hydrophilic by two different approaches. The addition of a positively charged ligand (cetyltrimethyl ammonium bromide, CTAB) and the ligand exchange procedure (2,3-dimercaptosuccinic acid, DMSA) have been successfully applied. The aqueous suspensions of NiFe₂O₄@CTAB and NiFe₂O₄@DMSA showed good colloidal stability after a long period of time. The different surface modification affected both the NMR relaxometric measurements and the hyperthermia effects. In both techniques CTAB modification demonstrated higher r₂ relaxivity (278.9 s⁻¹ mM⁻¹ in an NMR spectrometer at 11.7 T) and SAR values (423.4 W g⁻¹ at an applied AC field with a particle concentration of 0.5 mg mL⁻¹). The results indicate that a coating with a larger molecule as CTAB under the same size, shape and magnetization of NiFe₂O₄ NPs gave rise to NMR relaxometric properties and heating efficacy.

Two related single-molecule magnets, [Co(9Accm) ₂ (py) ₂ ] and [Co(9Accm) ₂ (2,2′-bpy)], with cis and trans disposition of the CCMoid ligands were studied in solution, in the solid state and by deposition on different surfaces.