Pressure generation and investigation of the post-perovskite transformation in MgGeO3 by squeezing the Kawai-cell equipped with sintered diamond anvils
Pressure generation and investigation of the post-perovskite transformation in MgGeO3 by squeezing the Kawai-cell equipped with sintered diamond anvils
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DOI：
10.1016/j.epsl.2010.02.023
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发表时间：
2010-04
影响因子：
5.3
通讯作者：
E. Ito;D. Yamazaki;T. Yoshino;H. Fukui;S. Zhai;Anton Shatzkiy;T. Katsura;Y. Tange;K. Funakoshi
中科院分区：
文献类型：
--
作者：
E. Ito;D. Yamazaki;T. Yoshino;H. Fukui;S. Zhai;Anton Shatzkiy;T. Katsura;Y. Tange;K. Funakoshi
高压产生已尝试使用配备烧结钻石方块的卡瓦伊电池和在Spring-8的同步辐射。根据Anderson等人的计算，在300K时，最大可达压力达到90.4 Gpa。(1989)Au刻度。同时，我们用原位X射线衍射法研究了镁GeO_3中钙钛矿(PV)-钙钛矿后钙钛矿(PPV)的转变，温度高达74 GPa2200K。在高于63 Gpa和1300K的压力和温度下，观察到了PV向PPV的转变。在所考察的温度范围内，正向反应和反向反应都被发现相当缓慢。我们通过PV或PPV相生长的条件和两相共存的条件来确定相边界，该条件由方程T(K)=177P(Gpa)−9677表示。我们对MgGeO_3的dp/dt斜率为5.6 Mpa/K，接近于对MgSiO_3的最小估计值，因此表明相对较深的D“不连续性和来自核心的高热流密度。我们强调，相边界完全取决于所采用的压力标度。
High pressure generation has been tried by using the Kawai-cell equipped with sintered diamond cubes and the synchrotron radiation at SPring-8. The maximum attainable pressure reached 90.4GPa at 300K based on the Anderson et al. (1989) Au scale. Simultaneously, we investigated the perovskite (Pv)–postperovskite (PPv) transformation in MgGeO3up to ca. 74GPa and 2200K by means of in situ X-ray diffraction method. Transformation from Pv to PPv was observed at pressures and temperatures higher than 63GPa and 1300K. Both the forward and the reverse reactions were found to be fairly sluggish over the examined temperature range. We determined the phase boundary by passing through the conditions at which either Pv or PPv phase grew and that of coexistence of both the phases, which is expressed by the equation T(K)=177 P(GPa)−9677. Our dP/dT slope of 5.6MPa/K for MgGeO3is close to the minimum estimate for MgSiO3and accordingly suggests relatively deeper D″ discontinuity and a high heat flux from the core. We emphasize that the phase boundary completely relies on the pressure scale adopted.