Designed single-source precursors for iron germanide nanoparticles: colloidal synthesis and magnetic properties

Area of Science:

• Nanomaterials Science
• Inorganic Chemistry
• Solid-State Chemistry

Background:

• Nanoscale synthesis of iron germanides presents significant challenges.
• Controlling phase purity and size distribution is crucial for their applications.

Purpose of the Study:

• To develop a reliable method for synthesizing hexagonal Fe1.67Ge nanoparticles.
• To investigate the influence of precursor structure on nanoparticle formation.

Main Methods:

• Thermolysis of single-source bimetallic precursors, specifically [{iPrNC(tBu)NiPr}RGe]Fe(CO)4.
• Characterization using spectroscopic techniques and single crystal X-ray diffraction.
• Computational studies to rationalize experimental observations.

Main Results:

• The precursor with R = N(SiMe3)2 yielded pure ferromagnetic Fe1.67Ge nanoparticles (mean diameter ~6 nm, narrow size distribution <12%).
• The precursor with R = Cl resulted in uncontrolled phases and broad size distributions.
• Ge-substituent bond energy was identified as a key factor influencing thermolysis outcomes.

Conclusions:

• The choice of the Ge-substituent in single-source precursors critically impacts the outcome of iron germanide nanoparticle synthesis.
• Mild thermolysis of carefully designed precursors offers a viable route to controlled synthesis of Fe1.67Ge nanoparticles.