Fei Qin , Xiang Wu , Shan Qin , Dongzhou Zhang , Vatali B. Prakapenka , Steven D. Jacobsen
{"title":"压力诱导屈光度脱水的单晶X射线衍射和拉曼光谱研究","authors":"Fei Qin , Xiang Wu , Shan Qin , Dongzhou Zhang , Vatali B. Prakapenka , Steven D. Jacobsen","doi":"10.1016/j.crte.2018.07.007","DOIUrl":null,"url":null,"abstract":"<div><p>We present a synchrotron-based, single-crystal X-ray diffraction and Raman spectroscopy study of natural green dioptase (Cu<sub>6</sub>Si<sub>6</sub>O<sub>18</sub>·6H<sub>2</sub>O) up to ∼30<!--> <!-->GPa at room temperature. The lattice parameters of dioptase exhibit continuous compression behavior up to ∼14.5<!--> <!-->GPa, whereupon a structural transition is observed. Pressure–volume data below 14.5<!--> <!-->GPa were fitted to a second-order Birch–Murnaghan equation of state with <em>V</em><sub>0</sub> <!-->=<!--> <!-->1440(2) Å<sup>3</sup> and <em>K</em><sub>0</sub> <!-->=<!--> <!-->107(2) GPa, with <em>K</em><sub>0</sub>′<!--> <!-->=<!--> <!-->4(fixed). The low-pressure form of dioptase exhibits anisotropic compression with axial compressibility <em>β</em><sub><em>a</em></sub> <!-->><!--> <em>β</em><sub><em>c</em></sub> in a ratio of 1.14:1.00. Based on the diffraction data and Raman spectroscopy, the new high-pressure phase could be regarded as a dehydrated form of dioptase in the same symmetry group. Pressure-induced dehydration of dioptase contributes broadly to our understanding of the high-pressure crystal chemistry of hydrous silicates containing molecular water groups.</p></div>","PeriodicalId":50651,"journal":{"name":"Comptes Rendus Geoscience","volume":"351 2","pages":"Pages 121-128"},"PeriodicalIF":2.0000,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.crte.2018.07.007","citationCount":"0","resultStr":"{\"title\":\"Pressure-induced dehydration of dioptase: A single-crystal X-ray diffraction and Raman spectroscopy study\",\"authors\":\"Fei Qin , Xiang Wu , Shan Qin , Dongzhou Zhang , Vatali B. Prakapenka , Steven D. Jacobsen\",\"doi\":\"10.1016/j.crte.2018.07.007\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We present a synchrotron-based, single-crystal X-ray diffraction and Raman spectroscopy study of natural green dioptase (Cu<sub>6</sub>Si<sub>6</sub>O<sub>18</sub>·6H<sub>2</sub>O) up to ∼30<!--> <!-->GPa at room temperature. The lattice parameters of dioptase exhibit continuous compression behavior up to ∼14.5<!--> <!-->GPa, whereupon a structural transition is observed. Pressure–volume data below 14.5<!--> <!-->GPa were fitted to a second-order Birch–Murnaghan equation of state with <em>V</em><sub>0</sub> <!-->=<!--> <!-->1440(2) Å<sup>3</sup> and <em>K</em><sub>0</sub> <!-->=<!--> <!-->107(2) GPa, with <em>K</em><sub>0</sub>′<!--> <!-->=<!--> <!-->4(fixed). The low-pressure form of dioptase exhibits anisotropic compression with axial compressibility <em>β</em><sub><em>a</em></sub> <!-->><!--> <em>β</em><sub><em>c</em></sub> in a ratio of 1.14:1.00. Based on the diffraction data and Raman spectroscopy, the new high-pressure phase could be regarded as a dehydrated form of dioptase in the same symmetry group. Pressure-induced dehydration of dioptase contributes broadly to our understanding of the high-pressure crystal chemistry of hydrous silicates containing molecular water groups.</p></div>\",\"PeriodicalId\":50651,\"journal\":{\"name\":\"Comptes Rendus Geoscience\",\"volume\":\"351 2\",\"pages\":\"Pages 121-128\"},\"PeriodicalIF\":2.0000,\"publicationDate\":\"2019-02-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.crte.2018.07.007\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Comptes Rendus Geoscience\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1631071318301123\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comptes Rendus Geoscience","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1631071318301123","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
Pressure-induced dehydration of dioptase: A single-crystal X-ray diffraction and Raman spectroscopy study
We present a synchrotron-based, single-crystal X-ray diffraction and Raman spectroscopy study of natural green dioptase (Cu6Si6O18·6H2O) up to ∼30 GPa at room temperature. The lattice parameters of dioptase exhibit continuous compression behavior up to ∼14.5 GPa, whereupon a structural transition is observed. Pressure–volume data below 14.5 GPa were fitted to a second-order Birch–Murnaghan equation of state with V0 = 1440(2) Å3 and K0 = 107(2) GPa, with K0′ = 4(fixed). The low-pressure form of dioptase exhibits anisotropic compression with axial compressibility βa > βc in a ratio of 1.14:1.00. Based on the diffraction data and Raman spectroscopy, the new high-pressure phase could be regarded as a dehydrated form of dioptase in the same symmetry group. Pressure-induced dehydration of dioptase contributes broadly to our understanding of the high-pressure crystal chemistry of hydrous silicates containing molecular water groups.
期刊介绍:
Created in 1835 by physicist François Arago, then Permanent Secretary, the journal Comptes Rendus de l''Académie des sciences allows researchers to quickly make their work known to the international scientific community.
It is divided into seven titles covering the range of scientific research fields: Mathematics, Mechanics, Chemistry, Biology, Geoscience, Physics and Palevol. Each series is led by an editor-in-chief assisted by an editorial committee. Submitted articles are reviewed by two scientists with recognized competence in the field concerned. They can be notes, announcing significant new results, as well as review articles, allowing for a fine-tuning, or even proceedings of symposia and other thematic issues, under the direction of invited editors, French or foreign.