Inversion degree, morphology and colorimetric parameters of cobalt aluminate nanopigments depending on reductant type in solution combustion synthesis

Spinel ferrite (AFe2O4)-based heterostructured designs for lithium-ion battery, environmental monitoring, and biomedical applications

“…In fact, the site occupation mainly depends on the electrostatic contribution to the lattice energy, the cation radii, cation charges, and crystal eld effects. In a typical spinel ferrite structure, the A 2+ cations are located at tetrahedral sites, while Fe 3+ cations are found at octahedral sites, for example in ZnFe 2 O 4 , which is similar to some other spinel crystalline structures such as CoAl 2 O 4 , 18 MgAl 2 O 4 , and Mn 3 O 4 . 19 For the inverse spinel structure, Fe 3+ cations are equally distributed between tetrahedral and octahedral sites while A 2+ cations only occupy octahedral sites, for example in NiFe 2 O 4 , CoFe 2 O 4 , 20,21 In 1945, L. Néel et al 16 investigated the exchange interactions and cationic distributions in spinel ferrite nanostructures to evaluate their magnetic properties.…”

Structural, Optical and Magnetic Properties of Diamagnetic Cd2+ Incorporated Cobalt Ferrite Thin Films Deposited by Spray Pyrolysis

“…63 The intrinsic stretching vibration bands of the metal were mostly detected at the tetrahedral site at 600-550 cm −1 and the octahedral widening site at 450-385 cm −1 . [64][65][66] Generally, in spinel ferrites the bond length of the metal-oxygen at tetrahedral site is significantly shorter than that of the octahedral site and thus the higher stretching frequency for the M-O bond at tetrahedral site. 67,68 However, in the current circumstance only a unique major band near 600 cm −1 was observed as the FTIR spectra were documented in the range of 500-4000 cm −1 .…”

Green nanoceramic pigments based on cobalt chromite doped with Al: Synthesis, characterisation and colour performance

“…The change in the band gap values would explain the colour variation of metal aluminates. Furthermore, this shift may be attributed to the difference in particle size and size distribution which can cause a variation of the optical spectra [25].…”

“…The focus of recent research has been on chemical synthesis, in which the powders are synthesised in liquid systems. Thus, several authors have proposed different synthesis routes, such as hydrothermal processes [20], coprecipitation [21], microemulsion [22], combustion [23][24][25] and sol-gel [26][27][28]. Amongst these methods is the polymerisable complex process using the polymeric precursor, in which the metal cations are homogeneously distributed within the polymer chain.…”