摘要
A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were investigated by variable temperature X-ray diffraction(XRD), scanning electron microscope(SEM) and variable temperature Raman spectra. The compound exhibits NTE properties in the orderly O' phase crystal structure. When the temperature is from 293 to 759 K, the ceramic NdMnO_(3) shows negative thermal expansion of-4.7×10^(-6)/K. As temperature increases, the ceramic NdMnO_(3) presents NTE property range from 759 to 1 007 K. The average linear expansion coefficient is-18.88×10^(-6)/K. The physical mechanism of NTE is discussed and clarified through experiments.
作者
李玉成
张扬
ZHANG Muqun
DUAN Rong
LIU Xiteng
LI Yucheng;ZHANG Yang;ZHANG Muqun;DUAN Rong;LIU Xiteng(Department of Avionics Engineering,Aviation Maintenance NCO Academy of Air Force Engineering University,Xinyang 464000,China)
