• 文献标题:   Direct growth of oriented nanocrystals of gamma-iron on graphene oxide substrates. Detailed analysis of the factors affecting unexpected formation of the gamma-iron phase
  • 文献类型:   Article
  • 作  者:   KHANNANOV A, KIIAMOV A, VALIMUKHAMETOVA A, VAGIZOV FG, DIMIEV AM
  • 作者关键词:  
  • 出版物名称:   NEW JOURNAL OF CHEMISTRY
  • ISSN:   1144-0546 EI 1369-9261
  • 通讯作者地址:   Kazan Fed Univ
  • 被引频次:   1
  • DOI:   10.1039/c9nj02903f
  • 出版年:   2019

▎ 摘  要

In bulk, face-centered gamma-iron exists only at temperatures above 917 degrees C, returning back to body-centered alpha-iron upon cooling below this temperature. In this work, we report formation of the gamma-iron phase at temperatures significantly lower than the 917 degrees C threshold in the form of nanoparticles. Moreover, the as-grown nanoparticles have specific orientation along the (002) plane as the result of the templating effect of the graphene oxide substrate. Also, we provide a complete account of the factors responsible for the formation of the gamma-phase. Namely, we demonstrate the role of the type of carbon substrate, and the effect of the temperature and time of annealing and the graphene oxide/iron ion ratio. We demonstrate that the gamma-phase is not formed when using three-dimensional forms of carbon, elucidating the "magic" role of graphene oxide in this process.