Structural features of epitaxial NiFe2O4 thin films grown on different substrates by direct liquid injection chemical vapor deposition

Structural characterization of epitaxial LiFe5O8 thin films grown by chemical vapor deposition

“…In the case of films, weak long-range ordering exist as the ½ g 400 superlattice spots are weak but are still visible and these spots are completely missing in the as-grown bulk crystal. Raman spectroscopy of LFO films grown on MgO by pulsed laser deposition suggested the presence of disorder [19]. However, the present electron diffraction study of CVD-grown films shows clear short-range ordering and weak long-range ordering.…”

“…2). Other than threading dislocations, dark diffused contrast areas can also be observed and this may be related to either antiphase domains or A site cation vacancies [18,19]. Fig.…”

Probing optical band gaps at the nanoscale in NiFe2O4 and CoFe2O4 epitaxial films by high resolution electron energy loss spectroscopy

“…14 In addition to this, nano-regions having significant tetrahedral A site cation deficiency are also observed. 15 Moreover, the structure may show variation from the ideal inverse spinel structure because of changes in the strain/lattice parameter induced by the substrate. For example, in one report it has been shown theoretically that the tensile strain stabilizes the normal spinel configuration over the inverse spinel structure for both NFO and CFO.…”

Effect of Bloch wave electron propagation and momentum-resolved signal detection on the quantitative and site-specific electron magnetic chiral dichroism of magnetic spinel oxide thin films

“…The confusion lies in the earlier work of authors who assumed that the tetrahedral atoms are like impurity sites and Bloch wave propagation through these can be ignored [45]. This is not true as one can clearly see the tetrahedral atoms along the zone axis imaging condition by HR-STEM, which suggests that the channeling through A site cations cannot be ignored relative to B sites [42,46]. However, if one considers all the sites then one can estimate such contributions not only at Bragg condition but as a function of deviation parameter, s [44].…”

“…The previously performed spatially resolved optical study by HREELS revealed that the films do not show any cation mixing and the stability of the inverse spinel structure is robust [20]. However, some A site cation vacancy regions are observed in this system [41,42]. EMCD experiments are carried out with two different diffracting vectors, 400 and 440 types and the corresponding extinction distances are ~95.5 and 78 nm -1 , respectively, which have been used in Fig.…”