Synthesis and evaluation of effective parameters in thermal expansion coefficient of Ln0.6Sr0.4Co0.2M0.8O3−���? (Ln = La,Nd and M = Mn,Fe) perovskite oxide

Bulletin of materials science

Zahra Khakpour¹  Amir Maghsoudipour¹  Fatemeh Heydari¹  Masoumeh Javaheri¹  Masoud Alizadeh¹ 

[1] Ceramic Division, Material and Energy Research Center, P. Box 31787-316, Karaj, Alborz, Iran$$Ceramic Division, Material and Energy Research Center, P. Box 31787-316, Karaj, Alborz, IranCeramic Division, Material and Energy Research Center, P. Box 31787-316, Karaj, Alborz, Iran$$

关键词: Thermal expansion coefficient;    perovskite;    bond strength;    chemical expansion.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

In this study, oxides Ln_0.6Sr_0.4Co_0.2M_0.8O_{3−ð�?��?} (Ln = La,Nd and M = Mn,Fe) have been prepared and characterized to study the influence of the different cations on thermal expansion coefficient (TEC). TEC decreases favourably with replacement of Nd³⁺ and Mn³⁺ ions in the lattice. Nd³⁺ leads to decreasing ionicity of the Lnâ€�?�O bond and phase transition from rhombohedral to orthorhombic. Structural parameters of compounds have been determined by X-ray diffraction (XRD). FT-IR analysis has been used to compare the bond strength of different cations in the lattice. Variations of lattice parameters of compounds have been monitored by in-situ XRD at different temperatures in order to study the thermo-chemical expansivity. Concentration of oxide ion vacancy has been determined by high temperature gravimetry. The results show more stability of Mn⁴⁺ ions in high temperature in comparison with Fe⁴⁺ ions, which suppreses the tendency to lose oxygen from the lattice with the increase in temperature.

【 授权许可】

Unknown