鲁与七坐标的超密聚合物,来自里斯火山口的鲁
A El Goresy1, M Chen, L Dubrovinsky
1Max-Planck-Institut für Chemie, J. Joachim-Becher-Weg 27, 55128 Mainz, Germany. goresy@mpch-mainz.mpg.de
Science (New York, N.Y.)
|August 25, 2001
概括
科学家们在德国里斯火山口的冲击岩石中发现了一种新的超密度的二氧化 (TiO2) 矿物. 这种baddeleyite类型的TiO2多态体比鲁提尔密度高11%,可以了解撞击事件期间的冲击压力.
科学领域:
- 矿物学是什么?矿物学是什么?
- 地质化学 地质化学
- 行星科学 行星科学
背景情况:
- 二氧化 (TiO2) 存在于多种多态形式,其中常见的是鲁.
- 受冲击的岩石提供了撞击事件极端压力和温度条件的证据.
研究的目的:
- 报道了一种新型的超密度TiO2多态体的发现和特征.
- 为了利用这个新的矿物阶段来限制里斯火山口的冲击条件.
主要方法:
- 微观分析了来自里斯火山口的震动的格内斯.
- 用X射线衍射 (XRD) 来确定晶体结构.
- 密度和细胞参数计算.
主要成果:
- 发现了一种具有单临床晶格的超密度后形TiO2多态,与baddeleyite (ZrO2) 具有同结构.
- 新阶段在极化光下表现出强烈的蓝色内部反射.
- 确定单元格参数:a = 4.606(2) Å,b = 4.986(3) Å,c = 4.933(3) Å,β = 99.17(6) °,空间组P2(1)/c. 在一个单元格中,一个单元格为一个单元格.
- 计算密度为4.72g/cm3,比鲁密度高11%.
- 鉴定了对X射线辐射的敏感性,导致对鲁的反转.
- 有限制的峰值冲击压力为1620 GPa,温度低于500°C.
结论:
- 发现baddeleyite类型的TiO2为撞击事件提供了一个新的高压指标.
- 这一发现完善了我们对在冲击条件下TiO2相变化的理解.
- 矿物质在里斯火山口岩石中的存在为撞击事件的强度提供了关键数据.
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