Ultra-high resolution steady-state micro-thermometry using a bipolar direct current reversal technique

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Suspended micro-thermometry is crucial for measuring thermal conductance in low-dimensional materials.
• Background thermal conductance and temperature fluctuations introduce significant errors in measurements.

Purpose of the Study:

• To develop a high-resolution thermal conductance measurement scheme.
• To improve the accuracy of thermal transport measurements in nanomaterials.

Main Methods:

• Utilized a bipolar direct current reversal technique to replace traditional lock-in techniques.
• Employed a suspended microdevice with integrated platinum resistors for heating and temperature sensing.

Main Results:

• Achieved temperature resolution of 1.0-2.6 mK and thermal conductance resolution of 1.7-26 pW/K across 30-375 K.
• Accurately determined and isolated background thermal conductance, improving measurement precision.
• Demonstrated an order of magnitude improvement in resolution compared to lock-in amplifier techniques.

Conclusions:

• The new technique offers enhanced accuracy for investigating phonon transport in nanomaterials.
• This high-throughput method simplifies the isolation of parasitic signals.
• Enables more precise fundamental studies of thermal properties in nanoscale materials.