Thermistors such as NiMn2O4 and Mn-Co-Ni-O are important spinel oxide-based materials with extensive application prospects in the fields of information and energy storage. Such spinel oxides can be deposited by sintering stoichiometric carboxylate metal salts. Preferred carboxylate used include formates, acetates, fumarates, succinates, oxalates, tartarates, and malonates. BioFM supplies the acetate, oxalate, tartarate and formate salts which provides high atom economies and excellent solubility which enables easy homogenization of mixed carboxylates salts before decomposition. Pure metal carboxylates are premixed, ground, and thermally decomposed to generate the spinel oxide thermistors. The benefits of using carboxylate precursors include:
Use stoichiometric formate and/or acetate precursors (affords easy tuning of oxide stoichiometries)
Formate/acetate precursors promote lower temperature conversion to spinel oxides
Due to high solubility of formate and acetate salts, metal oxide conversion can be done in solution
The use of formate/acetate precursors enables customization of spinel oxide blends. This facilitates the engineering of numerous, previously unavailable metal oxides.
Nontoxic CO2 and H2O are the primary decomposition products unlike the corrosive and harmful NOx or SOx produced from sulfate or nitrate precursor.
Sintering of metal carboxylates can be done below 400°C, which is less energy intensive than the 900°C or higher needed for metal oxide precursors.