A new method for determining sample thickness: A comparison to experimental results

Sample thickness is an important parameter in quantitative electron microscopy,. Several methods for determining sample thickness have been described previously. A theoretical method presented here utilizes the low loss region of the electron energy loss spectrum to calculate sample thickness. The method avoids many of the limitations of other methods and is applicable to a wide variety of samples. The method is compared to film thicknesses determined experimentally as described below.Chromium films were deposited simultaneously onto collodion supported TEM grids and cured epoxy blanks using a Denton Hi Res 100 coater equipped with a Syton quartz crystal monitor. The cured epoxy blanks were covered with a layer of unpolymerized epoxy that was then cured. The chromium sandwich was cross sectioned using ultramicrotomy techniques employing a diamond knife. Sections were produced which were as thin as possible (