摘要
HfMgMo（3-x）WxO（12） with x = 0.5, 1.0, 1.5, 2.0, and 2.5 are developed with a simple solid state method. With increasing the content of W, solid solutions of Hf Mg Mo3-xWx O12 crystallize in an orthorhombic structure for x≤2.0 and a monoclinic structure for x2.0. A near-zero thermal expansion（ZTE） is realized for HfMgMo（2.5）W（0.5）O（12） and negative coefficients of thermal expansion（NCTE） are achieved for other compositions with different values. The ZTE and variation of NCTE are attributed to the difference in electronegativity between W and Mo and incorporation of a different amount of W, which cause variable distortion of the octahedra and softening of the MoO4 tetrahedra, and hence an enhanced NCTE in the a- and c-axis and reduced CTE in the b-axis as revealed by Raman spectroscopy and x-ray diffraction.
HfMgMo（3-x）WxO（12） with x = 0.5, 1.0, 1.5, 2.0, and 2.5 are developed with a simple solid state method. With increasing the content of W, solid solutions of Hf Mg Mo3-xWx O12 crystallize in an orthorhombic structure for x≤2.0 and a monoclinic structure for x2.0. A near-zero thermal expansion（ZTE） is realized for HfMgMo（2.5）W（0.5）O（12） and negative coefficients of thermal expansion（NCTE） are achieved for other compositions with different values. The ZTE and variation of NCTE are attributed to the difference in electronegativity between W and Mo and incorporation of a different amount of W, which cause variable distortion of the octahedra and softening of the MoO4 tetrahedra, and hence an enhanced NCTE in the a- and c-axis and reduced CTE in the b-axis as revealed by Raman spectroscopy and x-ray diffraction.
作者
李涛
刘献省
程永光
葛向红
张孟迪
连虹
张莹
梁二军
李玉晓
Tao Li Xian-Sheng Liu Yong-Guang Cheng Xiang-Hong Ge Meng-Di Zhang Hong Lian Ying Zhang Er-Jun Liang Yu-Xiao Li(School of Physical Science ＆ Engineering and Key Laboratory of Materials Physics of Ministry of Education, Zhengzhou University, Zhengzhou 450052, China Henan Key Laboratory of Photovoltaic Materials and School of Physics and Electronics, Henan University, Kaifeng 475004, China School of Physical Science ＆ Engineering and Key Laboratory of Materials Physics of Ministry of Education, Zhengzhou University, Zhengzhou 450052, China)
基金
supported by the National Natural Science Foundation of China(Grant Nos.10974183 and 11104252)
the Key Natural Science Project of Henan Province,China(Grant No.142102210073)
the Doctoral Fund of the Ministry of Education of China(Grant No.20114101110003)
the Fund for Science & Technology Innovation Team of Zhengzhou,China(Grant No.112PCXTD337)
