Micrometer Sized Hexagonal Chromium Selenide Flakes for Cryogenic Temperature Sensors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Cryogenics

Background:

• High-sensitivity thermometers are crucial for studying quantum and classical phenomena at cryogenic temperatures.
• Existing cryogenic sensors often lack the required sensitivity or operate over a limited temperature range.

Purpose of the Study:

• To develop and characterize a novel nanoscale thermometer based on chromium selenide (Cr-Se) for cryogenic applications.
• To evaluate the sensitivity and temperature measurement capabilities of Cr-Se flakes in the cryogenic regime.

Main Methods:

• Synthesis of hexagonal Cr-Se flakes using physical vapor transport.
• Characterization using scanning electron microscopy, energy dispersive X-ray spectrometry, and X-ray photoelectron spectroscopy.
• Fabrication of sensors via dry transfer onto gold contacts and measurement of resistivity from 7 K to 300 K.

Main Results:

• Cr-Se flakes were successfully synthesized and characterized.
• Resistivity measurements showed excellent fit with exponential functions, enabling extrapolation down to tenths of a Kelvin.
• The logarithmic sensitivity of the Cr-Se sensor surpasses that of commonly used cryogenic thermometers.

Conclusions:

• Chromium selenide is a promising material for developing highly sensitive nanoscale thermometers for cryogenic measurements.
• The developed Cr-Se sensor offers superior performance for both classical and quantum cryogenic applications.
• This work paves the way for new cryogenic sensor technologies in scientific research and industry.