AFM and s-SNOM Data Processing using Gwyddion

Lars Mester – neaspec, attocube systems AG, Haar, Germany
key learning objectives:

Correct Data Interpretation and Adjustment: Understanding the need for and methods of correcting AFM data is essential. Phase jumps in AFM data can create artifacts that misrepresent the true surface features, and recognizing as well as correcting these with appropriate software tools is critical. The tutorial emphasized the use of Gwyddion for such corrections, demonstrating functions like 'level data by mean plane subtraction' and 'fix zero around mean' to correct phase images and remove artificial jumps, while stressing the importance of manually verifying these automatic corrections to avoid errors.

Normalization and Referencing in AFM Analysis: Normalizing AFM data allows for the comparison of measurements across different samples or conditions by bringing them to a common reference frame. The tutorial demonstrated how to normalize optical amplitude data using Gwyddion, by dividing by the average value of the reference area. This process gives physical meaning to relative measurements, such as comparing the amplitude on different materials or structures within the sample. The importance of choosing a representative and consistent reference area for normalization was highlighted.

Software Proficiency for Complex Data Analysis: The tutorial acknowledged the limitations of certain software like Gwyddion in processing complex-valued numbers, which can be crucial for some advanced AFM analyses such as those involving polaritons or Fourier transforms. For tasks that require complex data processing, alternative software such as MATLAB may be necessary. However, for routine and accessible AFM data processing, Gwyddion offers user-friendly tools and batch processing capabilities, illustrating the need for proficiency in multiple software platforms to accommodate a range of analytical needs in AFM studies.

Overall, the session underscored the importance of having both a theoretical understanding of AFM principles and practical skills in using AFM data processing software to ensure accurate and reliable results in materials characterization.

This video was recorded with the financial support of the Teaming for Excellence program (European Union Horizon 2020; GA 857543) during the Near-field Optical Nanoscopy Summer School (Donostia- San Sebastian; 6-9 June 2023) organized by neaspec/attocube AG, CIC nanoGUNE BRTA and the ENSEMBLE3 Centre of Excellence.