Silver behenate is a
silver
Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...
of the long-chain
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...
behenic acid
Behenic acid (also docosanoic acid) is a carboxylic acid, the saturated fatty acid with formula C21H43COOH. In appearance, it consists of white solid although impure samples appear yellowish.
Sources
At 9%, it is a major component of ben oil (or ...
. It is a possible low-angle
diffraction standard that was characterized using the
powder diffraction
Powder diffraction is a scientific technique using X-ray, neutron, or electron diffraction on powder or microcrystalline samples for structural characterization of materials. An instrument dedicated to performing such powder measurements is call ...
technique.
Description
With the
National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...
's standard reference material
silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ta ...
as an internal standard, the long spacing of silver behenate was accurately determined from the profile-fitted
synchrotron diffraction peaks, with d
001 = 58.380 (3) Å (5.8380(3) nm). This result was in agreement with that obtained from the CuKα pattern. The profile widths of the silver behenate peaks were found to be consistently larger than those of the silicon peaks, indicating significant line broadening for silver behenate. The average
crystallite
A crystallite is a small or even microscopic crystal which forms, for example, during the cooling of many materials. Crystallites are also referred to as grains.
Bacillite is a type of crystallite. It is rodlike with parallel longulites.
Stru ...
size along the long-spacing direction of silver behenate was estimated using the
Scherrer equation, giving ''D''(avg) = 900 (50) Å (85–95 nm).
Diffraction patterns obtained with 1.54 Å synchrotron and CuKα radiation showed thirteen reflections in the 2''θ'' range from 1.5° to 20.0°, which suggests that the compound is suitable for use as an angle-calibration standard for low-angle diffraction. However, care must be taken if silver behenate is to be used as a peak-profile calibration standard because of line broadening.
References
*
{{silver compounds
Silver compounds
Salts of carboxylic acids