Synthesis of nanocrystalline manganite powders via a gel auto-combustion process for NTC thermistor applications

The effect of Zn on the microstructure and electrical properties of Mn1.17−xNi0.93Co0.9ZnxO4 (0≤x≤0.075) NTC thermistors

“…The two separated phases were formed by the decomposition of the cubic spinel Mn 1.17−x Ni 0.93 Co 0.9 Zn x O 4 phase during sintering, which was closely associated with the loss of oxygen in ceramics [6,15,16,25]. A similar behavior was observed for the Mn 2.34−x Ni 0.66 Zn x O 4 (0 ≤ x ≤ 1.02) and Mn 2.34−x Ni 0.66 Zn x O 4 (x = 0, 0.5, and 1.0) [20,26]. Moreover, it is important to note that the added Zn affected neither the crystal structure nor the phase decomposition.…”

Glycine-assisted fabrication of nanocrystalline cobalt ferrite system

“…Conventionally, CoFe 2 O 4 nanopowder is fabricated by sol-gel method [6][7][8], co-precipitation method [9][10][11] and hydrothermal method [12,13]. However, the difficulty on the control of solution pH value during the chemical dynamic process, and the requirement of strict and sophisticated drying conditions as well as expensive alkoxide precursors, respectively, makes the coprecipitation and sol-gel methods not so effective for obtaining highly qualified CoFe 2 O 4 nanopowder.…”

Preparation of Ultra‐Fine Nickel Manganite Powders and Ceramics by a Solid‐State Coordination Reaction

“…There are two main methods used for preparation of powders for NTC ceramic thermistors, 5–8 namely, solid‐state processes and wet‐chemical processes. The solid‐state method involves mixing and milling of precursors, usually oxides or salts, at room temperatures and calcination at elevated temperatures during which the spinel structure is formed.…”