P-V-T relations of γ-Ca3(PO4)2 tuite determined by in situ X-ray diffraction in a large-volume high-pressure apparatus
P-V-T relations of γ-Ca3(PO4)2 tuite determined by in situ X-ray diffraction in a large-volume high-pressure apparatus
复制标题
DOI：
10.2138/am.2013.4403
复制
发表时间：
2013-10
影响因子：
3.1
通讯作者：
S. Zhai;D. Yamazaki;Weihong Xue;Lijin Ye;Chaowen Xu;S. Shan;E. Ito;A. Yoneda;T. Yoshino;Xinzhuan Guo;A. Shimojuku;N. Tsujino;K. Funakoshi
中科院分区：
文献类型：
--
作者：
S. Zhai;D. Yamazaki;Weihong Xue;Lijin Ye;Chaowen Xu;S. Shan;E. Ito;A. Yoneda;T. Yoshino;Xinzhuan Guo;A. Shimojuku;N. Tsujino;K. Funakoshi
摘要灰岩γ-Ca3(PO4)2是深部地幔中一种重要的磷矿物，是稀土元素、大离子亲石元素和磷的寄主。在本研究中，我们报告了合成γ-Ca3(PO4)2在高压和温度分别高达35.4 GPa和1300 K下的热弹性性能，并通过大体积多顶仪的原位能量色散X射线衍射测定。将得到的γ-Ca3(PO4)2的压力-体积-温度数据用高温Birch-Murnaghan状态方程拟合得到V2 = 447.4(4) Å3, KT0 = 100.8(18) GPa, KT0 = 5.74(13),(∂KT/∂T)P = -0.020(1) GPa/K, αT = 3.26（18） × 10-5 + 1.76（24） × 10-8 T。将所得数据拟合到mie - gren - deye状态方程得到γ0 = 1.35(6)， Θ0 = 944(136) K, q = 0.37（29）。在此基础上，计算了γ-Ca3(PO4)2灰岩沿典型冷、热板块的密度分布图，并与俯冲洋中脊玄武岩中共存硅酸盐矿物的密度分布图进行了对比。
Abstract Tuite, γ-Ca3(PO4)2, is regarded as an important phosphate mineral in the deep mantle playing a crucial role as a host for rare earth elements, large ion lithophile elements, and phosphorus. In this study we report the thermoelastic properties of synthetic γ-Ca3(PO4)2 at simultaneously high pressures and temperatures of up to 35.4 GPa and 1300 K, respectively, as determined by means of in situ energydispersive X‑ray diffraction in a large-volume multi-anvil apparatus. The pressure-volume-temperature data obtained for γ-Ca3(PO4)2 were fitted by the high-temperature Birch-Murnaghan equation of state to yield V2 = 447.4(4) Å3, KT0 = 100.8(18) GPa, K′T0 = 5.74(13), (∂KT/∂T)P = -0.020(1) GPa/K, and αT = 3.26(18) × 10-5 + 1.76(24) × 10-8 T. In addition, fitting the present data to the Mie-Grüneisen-Debye equation of state gives γ0 = 1.35(6), Θ0 = 944(136) K, and q = 0.37(29). Based on the thermoelastic properties obtained in our study, the density profiles of γ-Ca3(PO4)2 tuite along typical cold and hot slab geotherms were calculated and are compared with those of the coexisting silicate minerals in subducting mid-ocean ridge basalt.