Synthesis, Crystal Structure, and Transport Properties of the Hexagonal Mo₉ Cluster Compound Ag₃RbMo₉Se₁₁

Area of Science:

• Materials Science
• Solid State Physics
• Inorganic Chemistry

Background:

• Molybdenum-based cluster compounds are explored for high-temperature thermoelectric applications.
• Low lattice thermal conductivity is crucial for efficient thermoelectric materials.

Purpose of the Study:

• Investigate the crystal structure and transport properties of Ag3RbMo9Se11.
• Determine the thermoelectric performance of this compound at high temperatures.

Main Methods:

• Single-crystal X-ray diffraction was used to determine the crystal structure.
• Transport properties were measured across a wide temperature range (2–800 K).

Main Results:

• Ag3RbMo9Se11 crystallizes in the hexagonal space group P63/m.
• High atomic disorder and anisotropic thermal displacement lead to very low lattice thermal conductivity (0.6 W m−1 K−1 at 800 K).
• A maximum dimensionless thermoelectric figure of merit (ZT) of 0.4 was achieved at 800 K.

Conclusions:

• The unique crystal structure of Ag3RbMo9Se11 contributes to its excellent thermoelectric properties.
• This compound demonstrates significant potential for high-temperature thermoelectric energy conversion.