Effect of calcination conditions on phase formation and particle size of nickel niobate powders synthesized by solid-state reaction

Effect of niobate B-site precursors on phase formation and particle size of lead nickel niobate powders

“…In the temperature range from room temperature to ∼150 • C, both samples show small thermal peaks in the DTA curves, which are related to the first weight loss. These DTA peaks can be attributed to the decomposition of the organic species such as rubber lining from the milling process similar to our earlier reports [11][12][13][14]. By increasing the temperature up to ∼700 • C, the solid-state reaction occurs between oxide precursors.…”

“…This observation may be accounted by the fact that the columbite route possibly provides faster chemical reaction rate (only the reaction between PbO and NiNb 2 O 6 ) and is able to enhance the formation of perovskite PNN phase by increasing the reactivity of NiO [6]. Moreover, the minimum firing temperature required for the manufacturing of singlephase columbite NiNb 2 O 6 (∼950 • C [13]) is lower than that of corundum Ni 4 Nb 2 O 9 (∼1250 • C [14]). Therefore, in general, the methodology presented in this work provides a simple method for preparing perovskite PNN powders via a solid-state mixed oxide synthetic route.…”

“…Starting precursors were as follows: PbO (JCPDS file number 77-1971), NiO (JCPDS file number 73-1519) and Nb 2 O 5 (JCPDS file number 30-0873) (Aldrich, 99% purity). These three oxide powders exhibited an average particle size in the range [13,14], employing an optimized calcination conditions of 900 • C for 4 h with heating/cooling rates of 30 • C/min and 1050 • C for 2 h, with heating/cooling rates of 30 • C/min, respectively. The following reaction sequences were then proposed for the formation of PNN: …”

Influence of Ph and Calcination Temperature on Magnetic Properties of Nanosized Zn-Ferrite Synthesized by Sol–gel Citrate Method

“…Requirement of desirable microstructure: a high sintered density, a small particle size and a narrow particle size distribution is important in such applications [6]. Among ferrites, Zinc ferrite (ZnFe 2 O 4 ) is of particular interest because of its use as a magnetic material, thereby, requirement of fine control over its crystal size, crystallinity and phase purity of the nano-powder are important [7][8][9]. Phase formation, particle size and morphology of the ferrite powder depend on pH value of the initial solution, molar ratio of the ions and calcination temperature.…”

Molten salt synthesis and optical properties of Eu3+, Dy3+or Nd3+ doped NiNb2O6 columbite-type phosphors

“…There are a few methods to synthesize columbite nickel niobates such as a coprecipitation technique [14] and solid state reaction [15] in the literature. Generally, the mixed oxide method involves heating of a mixture of nickel oxide and niobium oxide at 1000 1C or above for long times, i.e., 6 h [16] and 12 h [17].…”