Hi, I'm struggling to convert my measured PFM amplitude to a useful piezoelectric coefficient d_33. I saw the formula by NanoSurf: d_33 = A*S/VAC, where A is the measured amplitude (microV), S the cantilever sensitivity (1.14pm/V), and VAC is the applied AC voltage (9V).

However, for my measured amplitude of 50microV I obtain a d_33 of 6.34E-6pm/V.

It seems to be wrong by E-6.

Does anybody know if I'm missing something?

Thanks in advance