Kelvin Probe Force Microscopy (KPFM)
Applications: Scanning probe microscopy (SPM), atomic force microscopy (AFM), contact and non-contact modes, Kelvin probe force microscopy (KPFM)
Measurements in atomic force microscopy are moving towards higher cantilever frequencies, multi-frequency, and multi-mode operation. Applications that previously performed on lock-in amplification below 1 MHz are moving into the regions of tens of MHz. Scientists demand scanning at ever increasing speeds and thus require instrumentation with small time constants, in order to capture very fast events.
| Objectives: | performing lock-in amplification at multiple frequencies in a sophisticated setup with multiple feedback loops |
| Benefits: | integrated solution for AFM oscillation control, including 2 lock-in amplifiers, 2 frequency generators, auxiliary outputs, a frequency response sweeper, and a programming environment to implement and execute custom control algorithms inside the measurement instrument (real-time control) - no need for additional costly real-time hardware |
| Relevant products: | HF2LI, HF2LI-MF, HF2LI-RT, HF2LI-UHS, HF2LI-PLL, HF2LI-PID |
HF2PLL Kelvin Probe Force Miscroscopy (KPFM) Mode
KPFM is a method to measure the electrical work function of a sample. This is done by finding the contact potential voltage by minimizing current flow through the tip. The challenge regarding the experimental setup is providing an additional electrical feedback to the sample and/or tip. This can easily be done using one of the four auxiliary outputs of the HF2LI and HF2PLL devices.
Key Features of the HF2PLL Phase-locked Loop for this Application
- 3 instruments in 1: double lock-in amplifier, double frequency generator, frequency response sweeper
- 1 µHz to 50 MHz frequency range
- 2 independent lock-in units
- 6 simultaneous frequencies
- Real-time programmability
- Integrated oscilloscope
- Ultra-high stability option