Understanding the Question: We are looking for the name of the error where a measurement's value depends on the direction or history of the scan.
Key Formulas and approach: This is a common phenomenon in sensors and actuators (like the piezo-scanners in AFMs) where the system lags behind the input signal.
Detailed Solution:
Step 1: Defining Hysteresis. Hysteresis is the dependence of a system's state on its past history.
Step 2: Scanning impact. If you scan a surface from left-to-right, and then right-to-left, the data points won't overlap exactly because the scanner doesn't return to the same spot for the same voltage.
Step 3: Identifying the term. This directional "lag" or "memory" is called Hysteresis.
Conclusion: The correct term is Hysteresis.