Negative Thermal Expansion Properties of Sm0.85Sr0.15MnO3-δ

Journal of Composites Science

Yang Zhang¹  Yucheng Li¹  Yifeng Wu¹  Yongtian Li¹ 

[1] Department of Avionics Engineering, Aviation Maintenance NCO Academy, Air Force Engineering University, Xinyang 464000, China;

关键词: negative thermal expansion;    Sm_0.85Sr_0.15MnO_3-δ;    lattice distortion;    oxygen defects;    Jahn–Teller effect;   

DOI  :  10.3390/jcs6060156

来源: DOAJ

【 摘 要 】

A novel negative thermal expansion (NTE) material composed of Sm_0.85Sr_0.15MnO_3-δ was synthesized using the solid-state method. By allowing Sr²⁺ to partially replace Sm³⁺ in SmMnO₃, the ceramic material Sm_0.85Sr_0.15MnO_3-δ exhibits NTE properties between 360K and 873K, and its average negative thermal expansion coefficient was −10.08 × 10⁻⁶/K. The structure of Sm_0.85Sr_0.15MnO_3-δ is orthogonal, the space group is pbnm, the morphology is regular, and the grain size is uniform. The results of X-ray diffraction and XPS (X-ray photoelectron spectroscopy) suggest that the NTE phenomenon is related to the electron transfer of Mn ions. With the increase in temperature, Mn⁴⁺ is rapidly transformed into Mn³⁺, accompanied by Mn⁴⁺O₆ octahedron distortion and oxygen defects. It was found that the sample volume continually decreased at the same time.

【 授权许可】

Unknown