Silicon Powder– NIST (WAXS peak at 2.0 1/Å)
Silicon powder, when prepared by NIST, is an excellent WAXS standard…..Homemade stuff, ground to a powder, however, not so great, due to strain induced during grinding or milling. So the NIST standard although expensive, is highly recommended. Given the narrow line width (compared to any resolution a SAXS/WAXS instrument will give you), it serves as a nice measure of not only q-spacing, but also of the system resolution. Please see our technical note and NIST documentation page for further information.