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The phase transition, bulk and lattice thermal expansion behaviour of the strontium and neodymium substituted lanthanum chromites have been studied by dilatometry and high temperature X-ray powder diffractometry from room temperature to 1123 and 1073 K, respectively, in static air. The studies revealed that the temperature of the orthorhombic to rhombohedral phase transition, which occurred at ∼550 K in undoped LaCrO 3 , decreased on substitution of Sr 2+ ions and increased on substitution of Nd 3+ ions, systematically. However, the coefficients of average linear and volume thermal expansion ( α l and α v ) of LaCrO 3 showed a marginal increase on Sr 2+ substitution to different extent, whereas a reverse trend was observed with Nd 3+ substitution. The phase transition temperatures and α l and α v of the compounds as determined by dilatometric and high temperature X-ray diffractometric methods are reported. |
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