A dilatometric study of the Lao.8Sr0.2MnO3 sintering behaviour

✍ Scribed by A. Poirson; P. Decorse; G. Caboche; L.C. Dufour

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 900 KB
• Volume: 99
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(97)00260-9

✦ Synopsis

The sintering behaviour of La,,,Sr,,,MnO, has been studied by dilatometry between 1100 and 1800 K in various oxygen potentials [pure oxygen, air and nitrogen (PO, = 1 X lo-' bar)]. The starting material was prepared by spray pyrolysis of aqueous solutions of nitrates. Two classical sinter stages, neck formation and grain growth respectively, were evidenced from dilatometric curves and this result was corroborated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The rate of densification was found to be directly dependent on oxygen partial pressure, the best conditions being in nitrogen. These results are discussed in terms of vacancy diffusion and oxygen stoichiometry linked to two factors: the initial (La+Sr)/Mn ratio and the Mn3+ /Mn4+ ratio determined both by temperature and oxygen partial pressure.