• Sodreau, Alexandre
• Madec, David
• Mallet-Ladeira, Sonia
• Miqueu, Karinne
• Lachaize, Sébastien
• Delpech, Fabien
• Nayral, Céline
• Sotiropoulos, Jean-Marc

Abstract

The synthesis of iron germanide nanoparticles at the nanoscale is a challenging task. Here, we describe the preparation of nanocrystals of the hexagonal Fe1.67Ge phase via the thermolysis of single source precursors [{iPrNC(tBu)NiPr}RGe]Fe(CO)4 (where R = Cl, N(SiMe3)2) under mild conditions (200 °C). These bimetallic precursors and the corresponding germylenes [{iPrNC(tBu)NiPr}RGe] were fully characterized by spectroscopic techniques as well as single crystal X-ray diffraction. While the structural features of the molecular species were shown to be almost identical, the results of the thermolysis were highly dependent on the nature of R. When R = Cl, multimodal size distributions and non-controlled phases were obtained. In contrast, the thermolysis of [{iPrNC(tBu)NiPr}{N(SiMe3)2}Ge]Fe(CO)4 yielded pure ferromagnetic Fe1.67Ge nanoparticles with a mean diameter close to 6 nm and a narrow size distribution (<12%). These results were rationalized in terms of Ge–substituent bond energy thanks to a computational study.

Topics

• nanoparticle
• impedance spectroscopy
• single crystal X-ray diffraction
• single crystal
• phase
• iron
• thermolysis