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Wet‐Chemical Synthesis of Nanoscale Iron Boride, XAFS Analysis and Crystallisation to α‐FeB
Author(s) -
Rades Steffi,
Kornowski Andreas,
Weller Horst,
Albert Barbara
Publication year - 2011
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201001072
Subject(s) - x ray absorption fine structure , transmission electron microscopy , amorphous solid , xanes , crystallography , annealing (glass) , crystallization , materials science , chemistry , chemical engineering , spectroscopy , nanotechnology , metallurgy , organic chemistry , physics , quantum mechanics , engineering
The reaction of lithium tetrahydridoborate and iron bromide in high boiling ether as reaction medium produces an ultrafine, pyrophoric and magnetic precipitate. X‐ray and electron diffraction proved the product to be amorphous. According to X‐ray absorption fine structure spectroscopy (XAFS) the precipitate has FeB structure up to nearly two coordination spheres around an iron absorber atom. Transmission electron microscopy (TEM) confirms the ultrafine powder to be nanoscale. Subsequent annealing at 450 °C causes the atoms to arrange in a more distinct FeB structure, and further thermal treatment to 1050 °C extends the local structure to the α‐modification of FeB. Between 1050 °C and 1500 °C α‐FeB is transformed into β‐FeB.