Biaxial atomically resolved force microscopy based on a qPlus sensor operated simultaneously in the first flexural...

Area of Science:

• Surface Science
• Nanotechnology
• Microscopy

Background:

• Frequency-modulation atomic force microscopy (AFM) typically measures vertical forces.
• Lateral force information is crucial for understanding many sample systems.
• Simultaneous lateral and vertical force measurement was previously limited to soft cantilevers and optical detection.

Purpose of the Study:

• To demonstrate the qPlus sensor's capability in a biaxial mode for simultaneous force component measurement.
• To adapt AFM for enhanced surface analysis by capturing lateral forces.
• To enable atomic resolution imaging using both vertical and lateral force data.

Main Methods:

• Utilizing the qPlus sensor in a biaxial mode with electrical detection.
• Employing the first flexural mode and the length extensional mode of the sensor.
• Describing the required electrode configuration and electrical detection circuit.

Main Results:

• Atomic resolution achieved on mica surfaces in ambient conditions.
• Atomic resolution achieved on silicon surfaces in ultra-high vacuum.
• Demonstrated the qPlus sensor's effectiveness in biaxial mode for capturing two independent force components.

Conclusions:

• The qPlus sensor can be effectively operated in a biaxial mode for simultaneous lateral and vertical force detection.
• This method allows for atomic resolution imaging across various environments (ambient, UHV).
• Existing qPlus AFM setups can be modified to incorporate this biaxial sensing capability.