Effects of Sr and Ni-Dopants on the Structure and Conductivity of Lanthanum Chromite
Compositions of lanthanum chromite substituted with Sr on the La site and Ni on the Cr site were synthesized by Citrate gel. The suitable calcination temperature of these compositions was 1100°C for 4 hrs to obtain a perovskite phase. The sample bars were formed by cold isostatic press and sintered at 1400°C for 5 hrs in air. The phase, microstructure, electrical conductivity were determined by XRD, dc four-probe as a function of temperature and their chemical compositions were identified by ICP analysis. The result of La0.9Sr0.1Cr0.5Ni0.5O3-δ shows the maximum conductivity of 72.76 Scm-1at 800°C in air. With further addition of Sr dopant, the conductivity of La0.8Sr0.2Cr0.5Ni0.5O3-δ decreases to a value of 54.98 Scm-1. In addition, the structure tends to change from orthorhombic to rhombohedral.
S. Suttiruengwong and W. Sricharussin
A. Ruangvittayanon and S. Kuharuangrong, "Effects of Sr and Ni-Dopants on the Structure and Conductivity of Lanthanum Chromite", Advanced Materials Research, Vols. 93-94, pp. 558-561, 2010