Method of collecting and processing electron diffraction data

1. A method for determining an atomic pair distribution function of a sample, comprising:

exposing the sample to an electron beam, wherein the sample scatters electrons from the electron beam;

detecting the scattered electrons with a detector, thereby obtaining a diffraction pattern of the sample;

manipulating at least one of the sample or the electron beam to limit exposure of at least a portion of the sample to the electron beam; and

analyzing the diffraction pattern to determine the atomic pair distribution function of the sample.

2. The method of claim 1 , wherein limiting the exposure of the portion of the sample comprises limiting the exposure to be below a critical electron dose.

3. The method of claim 2 , wherein the critical electron dose is a dose that causes less than 37% decay of the Bragg intensities.

4. The method of claim 2 , wherein the critical electron dose is a dose that causes less than a 37% change in the height of a peak in the PDF that is not a near-neighbor peak.

5. The method of claim 1 , wherein the diffraction pattern is obtained by a low-voltage electron microscope.

6. The method of claim 5 , wherein the electron microscope operates at a voltage lower than 80 kV.

7. The method of claim 1 , wherein the diffraction pattern is obtained by a transmission electron microscope.

8. The method of claim 1 , wherein the diffraction pattern is obtained by a transmission electron microscope that is equipped with an STEM unit.

9. The method of claim 1 , wherein a portion of the electron beam passes through the sample.

10. The method of claim 9 , wherein the electron beam impacts the center of the detector.

11. The method of claim 9 , wherein the electron beam impacts a corner of the detector.

12. The method of claim 9 , wherein the electron beam does not impact the detector.

13. The method of claim 1 , wherein the diffraction pattern is obtained in transmission geometry.

14. The method of claim 1 , wherein the diffraction pattern is obtained in reflection geometry.

15. The method of claim 1 , additionally comprising:

recording the location of the central beam relative to the detector;

and wherein the diffraction pattern comprises an electron diffraction image.

16. The method of claim 15 , wherein the analyzing step comprises:

azimuthally integrating the electron diffraction image, wherein the integration produces the integrated intensity as a function of an independent variable x; and

correcting the integrated intensity for intensity aberrations in the sample to obtain i(x).

17. The method of claim 1 , wherein the sample is an organic material.

18. The method of claim 1 , wherein the sample is an organometallic material.

19. The method of claim 1 , wherein the sample is a metal-organic complex.

20. A method for determining an atomic pair distribution function and for collecting electron diffraction data from multiple substantially unexposed areas of an organic or organometallic sample, comprising:

(a) illuminating an area of the organic or organometallic sample with an electron beam, wherein the beam has a diameter D 0 at an intersection with the sample;

(b) collecting electron diffraction data from the illuminated area of the sample, wherein the data is collected by a detector; and

(c) repeating steps (a)-(b) on areas of the sample that have not previously been illuminated.

21. The method of claim 20 , wherein the electron beam has a source and a selected area aperture with diameter D SA is present between the source and the sample.

22. A method for determining one or more atomic pair distribution functions associated with a material, comprising:

(a) identifying one or more regions of an organic or organometallic sample from which a signal is to be obtained;

(b) exposing the sample to a beam of electrons and obtaining a diffraction pattern of the sample;

(c) classifying each signal according to a classification scheme;

(d) determining the number of distinct structural forms that have been detected; and

(e) determining the PDF associated with each identified structural form.

23. The method of claim 22 , wherein the classifying step includes determining whether the diffraction pattern have distinct structural types, and further wherein the structural types are determined by examining an entire set of signals as a whole.

24. A method for determining an atomic pair distribution function of a sample, comprising:

exposing the sample to a beam of electrons, wherein the sample scatters electrons from the electron beam;

detecting the scattered electrons with a detector, thereby obtaining a diffraction pattern of the sample;

determining the atomic pair distribution function of the sample by analyzing the diffraction pattern.

25. A system for generating an atomic pair distribution function (PDF) associated with a sample, comprising:

a non-transitory computer-accessible medium which include instruction therein, wherein,

when the instructions are executed by a computing arrangement, the computing arrangement is configured to execute procedures comprising

obtaining a diffraction pattern from at least one portion of the sample to which electrons have been provided; and

determining the PDF associated with the sample by analyzing the diffraction pattern, procedure.