Pressure-induced phase transformation in β-eucryptite: An X-ray diffraction and density functional theory study

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• 作者：Yachao Chen^a ; Sukriti Manna^b ; Badri Narayanan^a ; ¹ ; Zhongwu Wang^c ; Ivar E. Reimanis^a ; ^{reimanis@mines.edu" class="auth_mail" title="E-mail the corresponding author} ; Cristian V. Ciobanu^b ; ^{cciobanu@mines.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Density functional theory ; XRD ; Eucryptite ; Ceramics
• 刊名：Scripta Materialia
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：122
• 期：Complete
• 页码：64-67
• 全文大小：844 K

文摘

Certain alumino-silicates display exotic properties enabled by their framework structure made of corner-sharing tetrahedral rigid units. Using in situ diamond-anvil cell x-ray diffraction (XRD), we study the pressure-induced transformation of β eucryptite, a prototypical alumino-silicate that undergoes a phase transformation at moderate pressures. The atomic structure and symmetry group of the new pressure-stabilized phase has not yet been reported. Based on density functional theory studies and Rietveld analysis of XRD patterns, we find that the new phase belongs to the Pna2 ₁ space group and report its atomic structure. Furthermore, we discover two other possible pressure-stabilized polymorphs, P1c1 and Pca2 ₁.