Surfactant-controlled composition and crystal structure of manganese(II) sulfide nanocrystals prepared by solvothermal synthesis

• Elena Capetti,
• Anna M. Ferretti,
• Vladimiro Dal Santo and
• Alessandro Ponti

Beilstein J. Nanotechnol. 2015, 6, 2319–2329, doi:10.3762/bjnano.6.238

• the surfactants adsorbed on the NCs. Keywords: manganese oxide; manganese sulfide; nanocrystal; polymorphism control; solvothermal synthesis; sulfur; surfactant; Introduction Manganese(II) sulfide (MnS) is a wide bandgap (Eg ≈ 3 eV) [1], p-type, antiferromagnetic semiconductor that crystallizes in

• oleylamine (100:1 with respect to Mn) [27]. Polymorphism control could also be achieved by chemical means. By reacting manganese(II) chloride and thiourea in an autoclave (T = 190 °C) for 12 h, 30 nm α-MnS NCs were prepared using water as a solvent, whereas when the solvent was benzene, γ-MnS rods (d = 40

• -MnS NCs only when OlAm was used. The γ-directing effect of amines observed with MnSt2 vanished when Mn2(CO)10 was used, pointing at an important role of the stearate ligand in the polymorphism control. The NCs were smaller and had a lower aspect ratio than the corresponding ones prepared starting from