Diffraction standard

{{Short description|Crystal used to calibrate an x-ray spectrometer}}

In crystallography, a diffraction standard, or calibration crystal, is a crystal used to calibrate an X-ray spectrometer to an absolute X-ray energy scale.{{Cite web |last=Swanson |first=H. E. |last2=McMurdie |first2=H. F. |last3=Morris |first3=M. C. |last4=Evans |first4=E. H. |date=June 1968 |title=Standard X-ray Diffraction Powder Patterns: Section 6. Data for 60 Substances |url=https://digital.library.unt.edu/ark:/67531/metadc13214/ |website=University of North Texas Libraries}} A range of materials may be used including quartz or silicon crystals.{{Cite web |last=Cline |first=James P. |date=September 6, 2016 |title=Powder Diffraction SRMs |url=https://www.nist.gov/programs-projects/powder-diffraction-srms |website=National Institute of Standards and Technology}} There are also reports of crystals of silver behenate or silver stearate having been used for this purpose.{{Cite journal |last=Blanton |first=T. N. |last2=Huang |first2=T. C. |last3=Toraya |first3=H. |last4=Hubbard |first4=C. R. |last5=Robie |first5=S. B. |last6=Louër |first6=D. |last7=Göbel |first7=H. E. |last8=Will |first8=G. |last9=Gilles |first9=R. |last10=Raftery |first10=T. |date=June 1995 |title=JCPDS—International Centre for Diffraction Data round robin study of silver behenate. A possible low-angle X-ray diffraction calibration standard |url=https://www.cambridge.org/core/product/identifier/S0885715600014421/type/journal_article |journal=Powder Diffraction |language=en |volume=10 |issue=2 |pages=91–95 |doi=10.1017/S0885715600014421 |issn=0885-7156|url-access=subscription }}{{Cite web |last=Finnefrock |first=A. C. |date=Jan 25, 2000 |title=SAXS Calibrants |url=http://bigbro.biophys.cornell.edu/documents/SAX_Calibrants/saxs_sphere.html}}