High-pressure and high-temperature polymorphism of Na₂CO₃ up to 10 GPa.

IF 2.5 3区化学 Q3 CHEMISTRY, MULTIDISCIPLINARY

Acta crystallographica Section B, Structural science, crystal engineering and materials Pub Date : 2026-08-01 Epub Date: 2026-06-23 DOI:10.1107/S2052520626004956

Benedetta Chrappan Soldavini, Marco Merlini, Chiara Mangano, Davide Comboni, Wilson Crichton, Michael Hanfland

{"title":"High-pressure and high-temperature polymorphism of Na2CO3 up to 10 GPa.","authors":"Benedetta Chrappan Soldavini, Marco Merlini, Chiara Mangano, Davide Comboni, Wilson Crichton, Michael Hanfland","doi":"10.1107/S2052520626004956","DOIUrl":null,"url":null,"abstract":"We report two new high-pressure polymorphs of sodium carbonate, ε and ε-II, stable over ∼2 GPa and 11 GPa, respectively. The ε polymorph exhibits a doubling of the c unit-cell parameter relative to the γ and β phases, crystallizes in space group Cc, and has a bulk modulus of 47.6 (8) GPa, comparable to that of the γ phase. Its stability is confirmed using in situ single-crystal and large-volume press (LVP) experiments. Phase transitions observed over a broad pressure-temperature range allow us to refine the topology of the Na2CO3 phase diagram. By integrating precise single-crystal constraints with LVP observations, we propose an updated phase diagram that shows an expanded stability field for the incommensurate γ phase, and reveals a wide stability field for the ε phase at conditions relevant for the Earth's mantle. These results provide improved experimental constraints for the high-pressure behavior of sodium carbonate.","PeriodicalId":7320,"journal":{"name":"Acta crystallographica Section B, Structural science, crystal engineering and materials","volume":" ","pages":"410-415"},"PeriodicalIF":2.5000,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13470794/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta crystallographica Section B, Structural science, crystal engineering and materials","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1107/S2052520626004956","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/6/23 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

We report two new high-pressure polymorphs of sodium carbonate, ε and ε-II, stable over ∼2 GPa and 11 GPa, respectively. The ε polymorph exhibits a doubling of the c unit-cell parameter relative to the γ and β phases, crystallizes in space group Cc, and has a bulk modulus of 47.6 (8) GPa, comparable to that of the γ phase. Its stability is confirmed using in situ single-crystal and large-volume press (LVP) experiments. Phase transitions observed over a broad pressure-temperature range allow us to refine the topology of the Na₂CO₃ phase diagram. By integrating precise single-crystal constraints with LVP observations, we propose an updated phase diagram that shows an expanded stability field for the incommensurate γ phase, and reveals a wide stability field for the ε phase at conditions relevant for the Earth's mantle. These results provide improved experimental constraints for the high-pressure behavior of sodium carbonate.

查看原文本刊更多论文

高达10 GPa的Na2CO3高压高温多态性。

我们报道了两种新的高压碳酸钠晶型ε和ε- ii，它们分别稳定在~ 2 GPa和11 GPa以上。与γ相和β相相比，ε晶型的c晶胞参数增加了一倍，在空间群Cc中结晶，体积模量为47.6 (8)GPa，与γ相相当。通过原位单晶实验和大体积压机（LVP）实验证实了其稳定性。在较宽的压力-温度范围内观察到的相变使我们能够改进Na2CO3相图的拓扑结构。通过将精确的单晶约束与LVP观测相结合，我们提出了一个更新的相图，显示了不相称的γ相的扩展稳定场，并揭示了与地幔相关条件下ε相的宽稳定场。这些结果为碳酸钠的高压行为提供了更好的实验约束。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Acta crystallographica Section B, Structural science, crystal engineering and materials CHEMISTRY, MULTIDISCIPLINARYCRYSTALLOGRAPH-CRYSTALLOGRAPHY

CiteScore

3.60

自引率

5.30%

发文量

期刊介绍： Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials publishes scientific articles related to the structural science of compounds and materials in the widest sense. Knowledge of the arrangements of atoms, including their temporal variations and dependencies on temperature and pressure, is often the key to understanding physical and chemical phenomena and is crucial for the design of new materials and supramolecular devices. Acta Crystallographica B is the forum for the publication of such contributions. Scientific developments based on experimental studies as well as those based on theoretical approaches, including crystal-structure prediction, structure-property relations and the use of databases of crystal structures, are published.