Composition-tuned Co(n)Si nanowires: location-selective simultaneous growth along temperature gradient.

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Chemistry

Background:

• Cobalt silicides (Co(n)Si) are technologically important materials with diverse crystal structures.
• Controlled synthesis of single-crystalline cobalt silicide nanowires (NWs) with specific compositions remains a challenge.

Purpose of the Study:

• To achieve simultaneous and selective synthesis of single-crystalline Co(n)Si NWs (n=1-3) with varying compositions.
• To report the crystal structures of Co(2)Si and Co(3)Si NWs for the first time.
• To investigate the electrical and magnetic properties of Co(2)Si NWs and compare them with CoSi NWs.

Main Methods:

• Utilizing a temperature gradient method with sapphire substrates for controlled synthesis.
• Employing techniques to tune the chemical composition during the synthesis of Co(n)Si NWs.
• Characterizing the crystal structures of the synthesized NWs, including bulk and nanostructure phases.

Main Results:

• Successfully synthesized single-crystalline Co(n)Si NWs (n=1-3) with simple cubic (CoSi), orthorhombic (Co(2)Si), and face-centered cubic (Co(3)Si) structures.
• Demonstrated the ability to tune the chemical composition of Co(n)Si NWs through the synthetic process.
• Reported the synthesis and detailed crystal structures of single-crystalline Co(2)Si and Co(3)Si NWs for the first time.
• Investigated and compared the electrical and magnetic properties of Co(2)Si NWs and CoSi NWs.

Conclusions:

• The temperature gradient method enables the selective synthesis of single-crystalline Co(n)Si NWs with controlled compositions.
• This work provides new insights into the crystal structures and properties of cobalt silicides at the nanoscale.
• The findings open avenues for exploring Co(n)Si NWs in various electronic and magnetic applications.