Example of TEM experiment

Identification of unknown phase in a BiFeO3 thin film


In an attempt to grow single phase BiFeO3 thin films a second unknown phase was found.

By use of maging in the TEM the size, morphology and position of the unknown phase could be described.

Energy dispersive spectroscopy (EDS) on single crystals of the unknown phase gave the composition BiFe2O5.

By tilting the sample and recording the diffraction patterns it was possible to construct the resiprocal lattice as illustrated in the figure under.

From the resiprocal lattice the Bravais lattice was identified as as primitive orthorombic. The cell parameters are related to the distance to the reflections in the diffraction pattern and was found to be a=6.04 Å b=7.94 Å c=8.66 Å.

Comparing this data with with previous published structures, showed that we had a a good match with Bi2Fe4O9 with spacegroup: Pbam