Near-zero thermal expansion in β-CuZnV₂O₇ in a large temperature range

【摘要】 We report a new type of near-zero thermal expansion material β-CuZnV₂ O₇ in a large temperature range from 173 K to 673 K.It belongs to a monoclinic structure（C2/c space group） in the whole temperature range.No structural phase transition is observed at atmospheric pressure based on the x-ray diffraction and Raman experiment.The high-pressure Raman experiment demonstrates that two structural phase transitions exist at 0.94 GPa and 6.53 GPa,respectively.The mechanism of negative thermal expansion in β-CuZnV₂ O₇ is interpreted by the variations of the angles between atoms intuitively and the phonon anharmonicity intrinsically resorting to the negative Grüneisen parameter.更多还原

【Abstract】 We report a new type of near-zero thermal expansion material β-CuZnV₂ O₇ in a large temperature range from 173 K to 673 K.It belongs to a monoclinic structure（C2/c space group） in the whole temperature range.No structural phase transition is observed at atmospheric pressure based on the x-ray diffraction and Raman experiment.The high-pressure Raman experiment demonstrates that two structural phase transitions exist at 0.94 GPa and 6.53 GPa,respectively.The mechanism of negative thermal expansion in β-CuZnV₂ O₇ is interpreted by the variations of the angles between atoms intuitively and the phonon anharmonicity intrinsically resorting to the negative Grüneisen parameter.更多还原