Negative thermal expansion property of Eu0.8Sr0·2MnO3-δ

We firstly synthesized the novel negative thermal expansion (NTE) material Eu0.8Sr0·2MnO3-δ with superior physical properties by solid state method. Apart from the NTE properties, the micro constitution and structure are also presented. It can be concluded from the analysis of XRD, SEM and the EDS that the dedicated material was composed of homogeneous polyhedral of Eu0.8Sr0·2MnO3-δ which occupies the characteristic structure of orthogonal perovskite. The thermal dilatometer test also presented a good performance on NTE property with the liner coefficient of thermal expansion (CTE) −14.0 ​× ​10−6 ​K−1 (298–873 ​K). Besides, we analyzed that the distortion effect (Jahn-Teller effect) and oxygen defects are both necessary conditions for this typical NTE property in terms of distortion of the structure of the perovskite by doping the Sr2+.