Fig. 7

Sample warping caused by the electron beam radiation can be simultaneously monitored and corrected for in the multiple tilt process. A The variations of \(n_{3,\omega }\) (green lines), defined in Eq. (10) and based on the linear portion of the computed projection maps, are a good indicator of the sample deformation happening over the course of the data acquisition. Its main behavior can be reproduced (doted blue lines) by considering a simple model having three deformation rates (\(\gamma _X\), \(\gamma _Y\) and \(\gamma _Z\)) allowing their estimates after an adjustment procedure. \(n_{3,\omega }\) oscillates between two curves as the many different tilt series (a, b,…, p) are successively acquired between −60° and +60°. The lower bound curve, reached at high tilt angles (\(|\theta | =\pi /3\)), specifically depends on the sample compression along the normal axis, while the upper bound curve, reached at zero tilt, only depends on the lateral compressions. B Representation of the amount of compression along the three main sample directions versus the micrograph index. In the stationary region, the sample compression is estimated to be 2–4 % in the lateral directions and 15 % along the normal axis