Strongly Absorbing Samples - Revision history

WikiSysop: /* Guidelines for 11-BM Mail-In Samples */

2013-04-29T22:56:01Z

Guidelines for 11-BM Mail-In Samples

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	===Guidelines for 11-BM Mail-In Samples===		===Guidelines for 11-BM Mail-In Samples===

	For its mail-in program, 11-BM uses a wavelength of ~ 0.41 Å (30 keV), and the standard supplied capillary tubes have a radius of 0.04 cm (~0.8 mm diameter).		For its mail-in program, 11-BM uses a wavelength of ~ 0.41 Å (30 keV), and the standard supplied capillary tubes have a radius of 0.04 cm (~0.8 mm diameter). Larger capillary tubes are now also [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Mail-In_Bases available].

	Use the convenient Absorb web utilty to estimate sample absorption:		Use the convenient Absorb web utilty to estimate sample absorption:

WikiSysop: /* Coated Capillary */

2012-09-26T17:45:41Z

Coated Capillary

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	'''NOTE 1''': this works for scans at room temperature and below (grease will become viscous at higher temperatures).		'''NOTE 1''': this works for scans at room temperature and below (grease will become viscous at higher temperatures).

	'''NOTE 2''': do not use some random grease you find in the lab. Dow Corning #4 silicone grease is good. Other silicone greases may also work. Bad choices include Vaseline and other high vacuum greases. These greases contain an crystalline phase which will add to the sample pattern. See an example of this plotted here for different greases measured at 11-BM (click for larger image).		'''NOTE 2''': do not use some random grease you find in the lab. Dow Corning #4 silicone grease is good. Other silicone greases may also work. Bad choices include Vaseline and other high vacuum greases. These greases contain an crystalline phase which will add peaks to the sample diffraction pattern. See an example of this plotted here for different greases measured at 11-BM (click for larger image).

	[[Image:GreasePlots.png\|100px\|GreasePlots.png]]		[[Image:GreasePlots.png\|100px\|GreasePlots.png]]

WikiSysop: /* Coated Capillary */

2012-09-26T17:45:07Z

Coated Capillary

← Older revision		Revision as of 17:45, 26 September 2012
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	'''NOTE 1''': this works for scans at room temperature and below (grease will become viscous at higher temperatures).		'''NOTE 1''': this works for scans at room temperature and below (grease will become viscous at higher temperatures).

	'''NOTE 2''': do not to use ~~just any~~ grease. Dow Corning #4 silicone grease is good. Other silicone greases may also work. Bad choices include Vaseline and other high vacuum greases. These greases contain an crystalline phase which will add to the sample pattern. See an example of this plotted here for different greases measured at 11-BM (click for larger image).		'''NOTE 2''': do not use some random grease you find in the lab. Dow Corning #4 silicone grease is good. Other silicone greases may also work. Bad choices include Vaseline and other high vacuum greases. These greases contain an crystalline phase which will add to the sample pattern. See an example of this plotted here for different greases measured at 11-BM (click for larger image).

	[[Image:GreasePlots.png\|100px\|GreasePlots.png]]		[[Image:GreasePlots.png\|100px\|GreasePlots.png]]

WikiSysop at 17:44, 26 September 2012

2012-09-26T17:44:34Z

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	Be sure to record the relative amounts of sample and dilution material to determine the average composition of your mixed powder. Once the mixed powder sample is loaded in a capillary, you can determine the actual packed density by measuring the total weight (minus the empty capillary) and volume of the packed sample (packed length * π * r<sup>2</sup>).		Be sure to record the relative amounts of sample and dilution material to determine the average composition of your mixed powder. Once the mixed powder sample is loaded in a capillary, you can determine the actual packed density by measuring the total weight (minus the empty capillary) and volume of the packed sample (packed length * π * r<sup>2</sup>).

			Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]

	====Coated Capillary====		====Coated Capillary====
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	====More Information====		====More Information====
	~~Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]~~

	~~====Additional information====~~
	* Wiki page on [https://wiki-ext.aps.anl.gov/ug11bm/index.php/X-ray_Absorption_and_Fluorescence X-ray_Absorption and Fluorescence]		* Wiki page on [https://wiki-ext.aps.anl.gov/ug11bm/index.php/X-ray_Absorption_and_Fluorescence X-ray_Absorption and Fluorescence]
	* Chapter on X-ray absorption in the [http://it.iucr.org/Cb/ch6o3v0001/ International Tables for Crystallography (2006). Vol. C, Chapter 6.3].		* Chapter on X-ray absorption in the [http://it.iucr.org/Cb/ch6o3v0001/ International Tables for Crystallography (2006). Vol. C, Chapter 6.3].

WikiSysop: /* More Information */

2012-09-26T17:43:54Z

More Information

← Older revision		Revision as of 17:43, 26 September 2012
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	Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]		Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]

	Additional information:		====Additional information====
	* Wiki page on [https://wiki-ext.aps.anl.gov/ug11bm/index.php/X-ray_Absorption_and_Fluorescence X-ray_Absorption and Fluorescence]		* Wiki page on [https://wiki-ext.aps.anl.gov/ug11bm/index.php/X-ray_Absorption_and_Fluorescence X-ray_Absorption and Fluorescence]
	* Chapter on X-ray absorption in the [http://it.iucr.org/Cb/ch6o3v0001/ International Tables for Crystallography (2006). Vol. C, Chapter 6.3].		* Chapter on X-ray absorption in the [http://it.iucr.org/Cb/ch6o3v0001/ International Tables for Crystallography (2006). Vol. C, Chapter 6.3].

WikiSysop at 17:43, 26 September 2012

2012-09-26T17:43:28Z

← Older revision		Revision as of 17:43, 26 September 2012
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	If in doubt, check the grease on your lab XRD machine first.		If in doubt, check the grease on your lab XRD machine first.


	====More Information====		====More Information====
	Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]		Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]

	Additional information ~~can be found within the~~ Wiki page on [https://wiki-ext.aps.anl.gov/ug11bm/index.php/X-ray_Absorption_and_Fluorescence X-ray_Absorption and Fluorescence]~~, and in the chapter~~ on X-ray absorption in the [http://it.iucr.org/Cb/ch6o3v0001/ International Tables for Crystallography (2006). Vol. C, Chapter 6.3].		Additional information:
			* Wiki page on [https://wiki-ext.aps.anl.gov/ug11bm/index.php/X-ray_Absorption_and_Fluorescence X-ray_Absorption and Fluorescence]
			* Chapter on X-ray absorption in the [http://it.iucr.org/Cb/ch6o3v0001/ International Tables for Crystallography (2006). Vol. C, Chapter 6.3].

	Please contact 11-BM staff if you have questions about sample preparation for highly absorbing materials		Please contact 11-BM staff if you have questions about sample preparation for highly absorbing materials


	===Examples===		===Examples===

WikiSysop: /* Numeric Examples */

2012-09-26T17:42:22Z

Numeric Examples

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	Example absorption calculations using Absorb web utility are shown below.		Example absorption calculations using Absorb web utility are shown below.
	----		----

	'''Example #1'''		'''Example #1'''
	Sample composition: C12H22O11 (Sucrose)		Sample composition: C12H22O11 (Sucrose)
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	'''Comments''': ''absorption is completely negligible, ignore. Note: samples with extremely low absorption may also be weakly scattering. In these cases, a larger diameter capillary may improve the counting statistics. Contact beamline staff if you have questions.		'''Comments''': ''absorption is completely negligible, ignore. Note: samples with extremely low absorption may also be weakly scattering. In these cases, a larger diameter capillary may improve the counting statistics. Contact beamline staff if you have questions.
	'''''		'''''

	----		----
	'''Example #2'''		'''Example #2'''
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	'''Comments''': ''absorption is in normal range, μ*r less than 1.0 - no problem for this experiment		'''Comments''': ''absorption is in normal range, μ*r less than 1.0 - no problem for this experiment
	'''''		'''''

	----		----
	'''Example #3'''		'''Example #3'''
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	'''Comments''': ''noticeable absorption, but can be used for analysis with an absorption correction term.		'''Comments''': ''noticeable absorption, but can be used for analysis with an absorption correction term.
	'''''		'''''

	----		----
	'''Example #4'''		'''Example #4'''
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	'''Comments''': ''absorption is too large (μ*r > 5.0), alternative sample preparations are needed (silica dilution etc).		'''Comments''': ''absorption is too large (μ*r > 5.0), alternative sample preparations are needed (silica dilution etc).
	'''''		'''''

	----		----
	'''Example #5'''		'''Example #5'''

WikiSysop at 17:42, 26 September 2012

2012-09-26T17:42:06Z

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	'''Example #2'''		'''Example #2'''
	Sample composition: Co3O4		Sample composition: Co3O4
	Use default Absorb web utility values 0.41 ~~Å~~, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: Co3O4 (theoretical density ~ 6.11 g/cm3)		Chemical Formula: Co3O4 (theoretical density ~ 6.11 g/cm3)
	Absorb web utility estimates μ = 20.95 cm-1 (estimated density ~ 5.7 g/cm3)		Absorb web utility estimates μ = 20.95 cm-1 (estimated density ~ 5.7 g/cm3)
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	'''Example #3'''		'''Example #3'''
	Sample composition: BaZr0.5Ti0.5O3		Sample composition: BaZr0.5Ti0.5O3
	Use default Absorb web utility values 0.41~~Å~~, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: BaZr0.5Ti0.5O3 (theoretical density ~ ?? g/cm3)		Chemical Formula: BaZr0.5Ti0.5O3 (theoretical density ~ ?? g/cm3)
	Absorb web utility estimates μ = 47.54 cm-1 (estimated density ~ 8.468 g/cm3)		Absorb web utility estimates μ = 47.54 cm-1 (estimated density ~ 8.468 g/cm3)
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	'''Example #4'''		'''Example #4'''
	Sample composition: PbZrO3		Sample composition: PbZrO3
	Use default Absorb web utility values 0.41 ~~Å~~, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: PbZrO3 (theoretical density ~ 9.8 g/cm3)		Chemical Formula: PbZrO3 (theoretical density ~ 9.8 g/cm3)
	Absorb web utility estimates μ = 158.50 cm-1 (estimated density ~ 11.2 g/cm3)		Absorb web utility estimates μ = 158.50 cm-1 (estimated density ~ 11.2 g/cm3)
	Total μ*r = 6.34		Total μ*r = 6.34
	'''Comments''': ''absorption is too large (μ*r > 5.0), alternative sample preparations are needed (silica dilution etc).		'''Comments''': ''absorption is too large (μ*r > 5.0), alternative sample preparations are needed (silica dilution etc).
			'''''
			----
			'''Example #5'''
			Sample composition: Eu11Cd6Sb12
			Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
			Chemical Formula: Eu11Cd6Sb12 (theoretical density ~ 9.8 g/cm3)
			Absorb web utility estimates μ = 191 cm-1 (estimated density ~ 21.8 g/cm3)
			Total μ*r = 7.64
			'''Comments''': ''extreme absorption!, alternative sample preparations are needed such as dilution + smaller capillaries and/or a hollow coated capillary approach described above.
	'''''		'''''
	----		----

WikiSysop at 17:38, 26 September 2012

2012-09-26T17:38:48Z

← Older revision		Revision as of 17:38, 26 September 2012
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	For samples with moderate absorption, peak intensities are still attenuated, but it is less dependent on scattering angle. Most refinement software packages can correct for this effect (or it can be incorporated in the refined atomic thermal parameters). For samples with low absorption, this effect is negligible and can be ignored.		For samples with moderate absorption, peak intensities are still attenuated, but it is less dependent on scattering angle. Most refinement software packages can correct for this effect (or it can be incorporated in the refined atomic thermal parameters). For samples with low absorption, this effect is negligible and can be ignored.

	The total absorption of any sample can be calculated before a measurement. It is a function of the sample composition, packed sample density, capillary radius, and the x-ray wavelength. One first determines the absorption for the composition and x-ray wavelength (μ), then calculates the total absorption (mu*r) for the actual sample to be measured using the capillary radius (r), sample density and packing fraction.		The total absorption of any sample can be calculated before a measurement. It is a function of the sample composition, packed sample density, capillary radius, and the x-ray wavelength. One first determines the absorption for the composition and x-ray wavelength (μ), then calculates the total absorption (μ*r) for the actual sample to be measured using the capillary radius (r), sample density and packing fraction.

	===Guidelines for 11-BM Mail-In Samples===		===Guidelines for 11-BM Mail-In Samples===
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	http://11bm.xor.aps.anl.gov/absorb/absorb.php		http://11bm.xor.aps.anl.gov/absorb/absorb.php

	==== Range of ~~Mu-R~~ values ====		==== Range of μ*r values ====

	The experimental implications for a range of sample absorption values (μ*r) are given below:		The experimental implications for a range of sample absorption values (μ*r) are given below:
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	Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: C12H22O11 (theoretical density ~ 1.6 g/cm3)		Chemical Formula: C12H22O11 (theoretical density ~ 1.6 g/cm3)
	Absorb web utility estimates Mu = 0.08 cm-1		Absorb web utility estimates μ = 0.08 cm-1
	Total ~~mu×r~~ = 0.01		Total μ*r = 0.01
	'''Comments''': ''absorption is completely negligible, ignore. Note: samples with extremely low absorption may also be weakly scattering. In these cases, a larger diameter capillary may improve the counting statistics. Contact beamline staff if you have questions.		'''Comments''': ''absorption is completely negligible, ignore. Note: samples with extremely low absorption may also be weakly scattering. In these cases, a larger diameter capillary may improve the counting statistics. Contact beamline staff if you have questions.
	'''''		'''''
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	'''Example #2'''		'''Example #2'''
	Sample composition: Co3O4		Sample composition: Co3O4
	Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: Co3O4 (theoretical density ~ 6.11 g/cm3)		Chemical Formula: Co3O4 (theoretical density ~ 6.11 g/cm3)
	Absorb web utility estimates Mu = 20.95 cm-1 (estimated density ~ 5.7 g/cm3)		Absorb web utility estimates μ = 20.95 cm-1 (estimated density ~ 5.7 g/cm3)
	Total ~~mu×r~~ = 0.84		Total μ*r = 0.84
	'''Comments''': ''absorption is in normal range, ~~mu×r~~ less than 1.0 - no problem for this experiment		'''Comments''': ''absorption is in normal range, μ*r less than 1.0 - no problem for this experiment
	'''''		'''''
	----		----
	'''Example #3'''		'''Example #3'''
	Sample composition: BaZr0.5Ti0.5O3		Sample composition: BaZr0.5Ti0.5O3
	Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: BaZr0.5Ti0.5O3 (theoretical density ~ ?? g/cm3)		Chemical Formula: BaZr0.5Ti0.5O3 (theoretical density ~ ?? g/cm3)
	Absorb web utility estimates Mu = 47.54 cm-1 (estimated density ~ 8.468 g/cm3)		Absorb web utility estimates μ = 47.54 cm-1 (estimated density ~ 8.468 g/cm3)
	Total ~~mu×r~~ = 1.90		Total μ*r = 1.90
	'''Comments''': ''noticeable absorption, but can be used for analysis with an absorption correction term.		'''Comments''': ''noticeable absorption, but can be used for analysis with an absorption correction term.
	'''''		'''''
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	'''Example #4'''		'''Example #4'''
	Sample composition: PbZrO3		Sample composition: PbZrO3
	Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: PbZrO3 (theoretical density ~ 9.8 g/cm3)		Chemical Formula: PbZrO3 (theoretical density ~ 9.8 g/cm3)
	Absorb web utility estimates Mu = 158.50 cm-1 (estimated density ~ 11.2 g/cm3)		Absorb web utility estimates μ = 158.50 cm-1 (estimated density ~ 11.2 g/cm3)
	Total ~~mu×r~~ = 6.34		Total μ*r = 6.34
	'''Comments''': ''absorption is too large (~~mu×r~~ > 5.0), alternative sample preparations are needed (silica dilution etc).		'''Comments''': ''absorption is too large (μ*r > 5.0), alternative sample preparations are needed (silica dilution etc).
	'''''		'''''
	----		----

WikiSysop at 17:36, 26 September 2012

2012-09-26T17:36:26Z

← Older revision		Revision as of 17:36, 26 September 2012
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	To decrease the μ*r of a highly absorbing sample, one must lower its effective packed density or reduce its radius.		To decrease the μ*r of a highly absorbing sample, one must lower its effective packed density or reduce its radius.

	====Dilution:====		====Dilution====
	One trick is dilute your sample by mixing with a lower density and amorphous material (no extra Bragg peaks!) to lower the overall absorption. Good candidates for this dilution method include silica (SiO2 glass) powder (you can grind it by hand using a mortar and pestle) or amorphous boron.		One trick is dilute your sample by mixing with a lower density and amorphous material (no extra Bragg peaks!) to lower the overall absorption. Good candidates for this dilution method include silica (SiO2 glass) powder (you can grind it by hand using a mortar and pestle) or amorphous boron.

	====Nested Capillary:====		====Nested Capillary====
	An absorbing powder sample could also be loaded into a [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Supplies_and_Tools smaller diameter capillary], which is then inserted into the standard 11-BM Kapton tube.		An absorbing powder sample could also be loaded into a [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Supplies_and_Tools smaller diameter capillary], which is then inserted into the standard 11-BM Kapton tube.

	Be sure to record the relative amounts of sample and dilution material to determine the average composition of your mixed powder. Once the mixed powder sample is loaded in a capillary, you can determine the actual packed density by measuring the total weight (minus the empty capillary) and volume of the packed sample (packed length * π * r<sup>2</sup>).		Be sure to record the relative amounts of sample and dilution material to determine the average composition of your mixed powder. Once the mixed powder sample is loaded in a capillary, you can determine the actual packed density by measuring the total weight (minus the empty capillary) and volume of the packed sample (packed length * π * r<sup>2</sup>).

	====Coated Capillary:====		====Coated Capillary====
			In extreme cases for samples with very high absorption one might consider coating the inside of the Kapton capillary with a layer of sample powder mixed with a silicone grease. Or coating the outside of a smaller diameter nested capillary. The sample powder must be inside the supplied Kapton tube for mail-in samples.

			Using this approach you essentially end up with a hollow tube of sample powder. This gives a good sized sample target with good powder averaging statistics, but without the absorption problems of a solid sample.

			'''NOTE 1''': this works for scans at room temperature and below (grease will become viscous at higher temperatures).

			'''NOTE 2''': do not to use just any grease. Dow Corning #4 silicone grease is good. Other silicone greases may also work. Bad choices include Vaseline and other high vacuum greases. These greases contain an crystalline phase which will add to the sample pattern. See an example of this plotted here for different greases measured at 11-BM (click for larger image).

	====More Information:====		[[Image:GreasePlots.png\|100px\|GreasePlots.png]]

			If in doubt, check the grease on your lab XRD machine first.


			====More Information====
	Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]		Read our [https://wiki-ext.aps.anl.gov/ug11bm/index.php/Nesting_Glass/Quartz_Capillaries_in_Kapton_Tubes guidelines on nesting capillaries]

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	Please contact 11-BM staff if you have questions about sample preparation for highly absorbing materials		Please contact 11-BM staff if you have questions about sample preparation for highly absorbing materials



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	----		----
	'''Example #3'''		'''Example #3'''
	Sample composition: BaZr0.5Ti0.~~5O33~~		Sample composition: BaZr0.5Ti0.5O3
	Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: BaZr0.5Ti0.5O3 (theoretical density ~ ?? g/cm3)		Chemical Formula: BaZr0.5Ti0.5O3 (theoretical density ~ ?? g/cm3)
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	----		----
	'''Example #4'''		'''Example #4'''
	Sample composition: ~~PbZrO33~~		Sample composition: PbZrO3
	Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction		Use default Absorb web utility values 0.41 Å, 0.4 mm, 0.6 packing fraction
	Chemical Formula: PbZrO3 (theoretical density ~ 9.8 g/cm3)		Chemical Formula: PbZrO3 (theoretical density ~ 9.8 g/cm3)