8230
The controllable fabrication of self - scrolling SiGe / Si / Cr helical nanoribbons on Si ( 111 ) substrates is investigated .
 Chemical: SiGe; Chemical: Si; Chemical: Cr; Chemical: Si
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: SiGe; Chemical: Si; Chemical: Cr; Chemical: Si