Isovalent Doping Strategy for Manganese Introduction into III-V Diluted Magnetic Semiconductor Nanoparticles: InP:Mn

III−V based diluted magnetic semiconductor (DMS) nanoparticles of In (1 - x ) Mn x P ( x ≤ 0.0135) have been prepared by slow heating of the reagents in trioctylphosphine oxide (TOPO) or by high-temperature injection of reagents dissolved in trioctylphosphine (TOP) into hot TOPO. The materials were prepared using either Mn(II) or Mn(III) salts as dopants and the resulting nanoparticles have diameters ranging from 2.95 ± 0.39 to 4.77 ± 0.73 nm, as determined from transmission electron micrographs. Chemical analysis of surface-exchanged samples revealed the incorporation of Mn into the crystal lattice with up to 6 Mn atoms per 3.4-nm diameter particle, or the equivalence of ∼10 20 Mn atoms/cm 3 in a zinc blende bulk lattice. The InP:Mn nanoparticles exhibited a red shift in the room-temperature photoluminescence of 0.02−0.03 eV relative to that for pure InP nanoparticles. Electron paramagnetic resonance studies suggest that the Mn atoms mostly reside near the surface and are Mn 2+, regardless of the oxidation state of the precursor. The magnetic susceptibility of surface-exchanged nanoparticles doped with Mn(III) exhibited a paramagnetic behavior with a magnetic moment of 5.9 μ B /Mn atom, consistent with 5 unpaired spins ( S = 5/2 state). The successful incorporation of isovalent Mn to produce Mn 2+ with a corresponding hole may represent a valuable strategy for production of ferromagnetic DMS nanoparticles based on arsenide systems, where the hole is coupled to the metal center and delocalized through the pnictide framework.