Preparation and characterisation of lanthanum nickel strontium oxides by combined coprecipitation and molten salt reactions

Lanthanum nickel strontium oxides have been prepared by combined precipitation and molten salt reactions at 1073 K to obtain fine lanthanum nickel strontium oxides with a uniform particle size at 0.1 μm. The Sr2+-doped LaNiO3 is more stable at high temperature than the undoped one. The powders coprecipitated with sodium hydroxide have good sinterability leading to lower electrical resistivity for La2NiO4 than for LaNiO3. Sr2+-doping of La2NiO4 to La2(1-x)NiSr2xO4 could reduce the electrical resistivity from 2.80×10−3 Ωradical dotm (x=0) to 3.16×10−4Ωradical dotm (x=0.30). These compounds with different compositions exhibit the characteristics of Pauli paramagnetic materials. In correspondence with the change of phase ratios there are also changes in the mass susceptibility for LaNiO3 from 2.23×10−6 (emu/Gauss-g) to 4.17×10−6 (emu/Gauss-g).