X

X-ray Diffraction

Points to ponder:

	How are the x-rays generated?
	Give a diagram of the machine and a description of how it works.
	Why are there two peaks for some orders? Whay do they only show up at large diffraction angles?
	Why do the peaks for graphite appear so different from the peaks for tungsten?
	Why, in the electron diffraction experiment, do we only get two peaks? Which ones are they? Do we see them with the X-rays?

You will want to determine values such as

(For a NYT article, you may not need to calculate all of these values, depending on the focus of your report).

References:

	Kingery, Bowen, Uhlmann, Introduction to Ceramics, excerpt.
	ASM, Metals Handbook.
	Kittel, Charles, Solid State Physics, excerpt.
	Trigg, Landmark Experiments in 20^th Century Physics, "The Wave Nature of X-rays."
	Atkins, Physical Chemistry. (Useful for background and has a good description of spin-orbital coupling).
	Zumdahl, Introduction to Chemistry. A good introductory chemistry text.
	CRC Press, Handbook of Chemistry and Physics.

Data Analysis

For your data analysis, you should probably download the full size image (in Adobe Acrobat format) and print them out:

Tungsten diffraction graph.

Graphite diffraction graph, filtered.

Graphite diffraction graph.

Tungsten

Peak Data (Extracted from the graph)
#	2 (Peak)	2 (Centroid)	d spacing	Local Bkgrd	Peak Height	% of max	Area	% of max	FWHM
1	40.246	40.244	2.xxx	26	100070	100.0	2518	100.0	0.225
2	58.206	58.232	1.xxx	28	2053	20.4	618	24.5	0.271
3	73.107	73.115	1.xxx	38	4670	46.4	1223	48.6	0.236
4	86.905	86.909	1.xxx	34	1517	15.1	409	16.2	0.243
5	87.185	87.175	1.xxx	33	819	8.1	238	9.5	0.262*
6	100.510	100.530	1.xxx	36	2183	21.7	736	29.2	0.303
7	100.850	100.845	0.xxx	37	1266	12.6	448	17.8	0.318
8	114.797	114.812	0.xxx	30	699	6.9	245	9.7	0.315
9	115.209	115.203	0.xxx	36	354	3.5	151	6.0	0.384*

* - Likely K_,2 peaks.

Tungsten X-ray Line card

JCPDS-ICDD PDF-2, Sets 1-45. (Quality: *)
Swanson, Tatge, NIST Circ. 529, 1 28 (1953)

Radiation	Cu K₁	dA	Int.	h	k	l
Lambda	1.54505	2.238	100	1	1	0
System	Cubic	1.582	15	2	0	0
Molecular Wt.	183.85	1.292	23	2	1	1
a	3.1648	1.1188	8	2	2	0
		1.0008	11	3	1	0
Color	Gray metallic	0.9137	4	2	2	2
CAS #	7440-33-7	0.8459	18	3	2	1
Merck Index 8th ed.	p. 1087	0.7912	2	4	0	0

Pattern @ 26C. Sample prepared at Westinghouse Electric Corp. Analysis of sample showed SiO2 0.04%, K 0.05%, Mo and Al2O3 0.01%.

Graphite

Peak Data (Extracted from the graph)
#	2 (Peak)	2 (Centroid)	D spacing	Local Bkgrd	Peak Height	% of max	Area	% of max	FWHM
1	26.494	26.465	3.xx	116	6299	100.0	3960	100.0	0.566
2	35.043	35.020	2.xx	54	123	2.0	37	0.9	0.271
3	42.825	42.325	2.xx	161	123	2.0	29	0.7	0.212
4	43.898	43.902	2.xx	144	158	2.5	145	3.7	0.826
5	54.499	54.496	1.xx	117	418	6.6	310	7.8	0.667
6	61.752	61.758	1.xx	99	75	1.2	23	0.6	0.276
7	73.003	72.984	1.xx	63	73	1.2	18	0.5	0.22
8	77.398	77.403	1.xx	80	352	5.6	197	5.0	0.504
9	83.501	83.500	1.xx	110	211	3.3	120	3.0	0.512
10	86.718	86.720	1.xx	116	36	0.6	8	0.2	0.200

* - Likely K₂ peaks.

Carbon (Graphite) X-ray Line card

JCPDS-ICDD PDF-2, Sets 1-45. (Quality: C)		dA	Int.	h	k	l
Holcombe, Private Communication, 1974		3.348	100	0	0	3
		2.081	11	1	0	1
Radiation	Cu K	1.958	9	0	1	2
System	Rhombohedral (Hex)	1.674	6	0	0	6
Molecular Wt.	12.01	1.623	4	1	0	4
Lambda	1.54178	1.460	2	0	1	5
a, b	2.456	1.228	4	1	1	0
c	10.044	1.190	1	1	0	7
		1.153	6	1	1	3
		1.116	1	0	0	9
		1.081	1	0	1	8
		0.9902	4	1	1	6
		0.8370	1	0	0	12
		0.8259	4	1	1	9
		0.8014	1	2	1	1
		0.7938	1	1	2	2