The disclosure includes novel polymorphic and pseudopolymorphic crystalline forms of 5-azacytidine, along with methods for preparing said forms, wherein 5-azacytidine is represented by the formula:The disclosure also includes pharmaceutical compositions comprising said forms. A preselected pattern is generated on the thin-film graphitic layer. The fibers are bonded together with a matrix, and a thermal link connects the bonded fibers to a cryogenic cold head.