2520
The variation of the surfactants having surface - binding functional groups modified not only the static magnetization but also the dynamics of the recovery of the magnetization occurring via spin - lattice relaxation in the photoexcited Fe3O4 nanocrystals .
 Chemical: Fe3O4
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: Fe3O4