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A Simple Question

Question: Imagine that you find a bottle labelled "metal standard" containing a metallic powder. You collect its powder diffraction pattern on a diffractometer up to an angle of 97° 2θ using an X-ray wavelength of 1.542Å. Standard data treatment afterwards yields the following list of peaks in terms of 2θ (in degrees) and I (Intensity in counts per second):

2θ: 36.30 39.08 43.33 54.35 70.09 70.74 77.13 82.18 83.89 86.66 90.00 95.01
I: 4750 3975 9450 2820 2340 1890 70 1985 575 1510 200 475

Suspecting that the bottle label is accurate, you collect the Hanawalt index entries for all the common metals. These are given below:

File No.
*Aluminum : Al   2.34x   2.025   1.222   4- 787
* Chromium :/Chromium syn               Cr (2B)   2.04x   1.183   1.442   6- 694
* Cobalt : Co (4F)   2.05x   1.774   1.253   15- 806
* Copper :/Copper syn Cu  2.09x   1.815   1.282   4- 836
*Gold :/Gold syn Au   2.36x   2.045   1.234   4- 784
* Iron :/Iron syn α-Fe (2B)   2.03x   1.173   1.432   6- 696
* Lead :/Lead syn Pb   2.86x   2.485   1.493   4- 686
* Nickel :/Nickel syn Ni   2.03x   1.764   1.252   4- 850
* Silver :/Silver syn Ag  2.36x   2.044   1.233   4- 783
* Tin :/Tin syn Sn   2.92x   2.799   2.027   4- 673
* Titanium : Ti   2.24x   2.563   2.343   5- 682
* Zinc :/Zinc syn Zn   2.09x   2.475   2.314   4- 831
©ICDD 1967. Used with permission from the International Centre for Diffraction Data.

The problem posed is "identify the sample and comment on the result".

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© Copyright 1997-2006.  Birkbeck College, University of London.
  		Author(s): Paul Barnes
Martin Vickers