16458
A transition from soft to exchange coupled to hard magnetic properties was obtained by varying the composition of NdxFe1 - xB8 ( x varies from 7 % to 40 % ) .
 Chemical: NdxFe1 - xB8
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: NdxFe1 - xB8