Yurii V. Seryotkin, Igor N. Kupriyanov, Mark A. Ignatov
{"title":"缺钾氟磷灰石-(K)的单晶x射线衍射和红外光谱研究","authors":"Yurii V. Seryotkin, Igor N. Kupriyanov, Mark A. Ignatov","doi":"10.1007/s00269-022-01229-y","DOIUrl":null,"url":null,"abstract":"<div><p>Three samples of fluorapophyllite-(K) with different cation composition were studied by the X-ray diffraction and IR-spectroscopy methods. The samples (K<sub>0.72</sub>(NH<sub>4</sub>)<sub>0.20</sub>)<sub>Σ0.92</sub>Na<sub>0.08</sub> Ca<sub>4</sub>[Al<sub>0.04</sub>Si<sub>7.96</sub>O<sub>20</sub>]F·8H<sub>2</sub>O from Nidym and K<sub>0.87</sub>Na<sub>0.06</sub> Ca<sub>4</sub>[Si<sub>8</sub>O<sub>20</sub>]F·8H<sub>2</sub>O from Akhaltsykhe localities are characterized by the deficiency of large cations K<sup>+</sup> and (NH<sub>4</sub>)<sup>+</sup> in the A site; the chemical composition of Talnakh sample (K<sub>0.94</sub>(NH<sub>4</sub>)<sub>0.06</sub>)<sub>Σ1.00</sub> Ca<sub>4</sub>[Si<sub>8</sub>O<sub>20</sub>]F·8H<sub>2</sub>O is close to the stoichiometric one. The large cations deficiency in the structure of Nidym and Akhaltsykhe samples is compensated by the presence of medium-sized Na<sup>+</sup> cations, located 1.12–1.31 Å away from the A position. The planar coordination of Na is formed by four H<sub>2</sub>O molecules. The occurrence of ammonium ions is found for the Nidym and Talnakh samples and their concentrations are estimated from the IR spectra and structure refinement. Polarized infrared measurements performed for fluorapophyllite-(K) samples oriented along the <i>c</i>-axis reveal pleochroic behavior of the OH absorption bands. The observed pleochroism is explained in terms of absorption from two OH vectors of the H<sub>2</sub>O molecules in the crystal structure.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2023-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Single-crystal X-ray diffraction and IR-spectroscopy studies of potassium-deficient fluorapophyllite-(K)\",\"authors\":\"Yurii V. Seryotkin, Igor N. Kupriyanov, Mark A. Ignatov\",\"doi\":\"10.1007/s00269-022-01229-y\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Three samples of fluorapophyllite-(K) with different cation composition were studied by the X-ray diffraction and IR-spectroscopy methods. The samples (K<sub>0.72</sub>(NH<sub>4</sub>)<sub>0.20</sub>)<sub>Σ0.92</sub>Na<sub>0.08</sub> Ca<sub>4</sub>[Al<sub>0.04</sub>Si<sub>7.96</sub>O<sub>20</sub>]F·8H<sub>2</sub>O from Nidym and K<sub>0.87</sub>Na<sub>0.06</sub> Ca<sub>4</sub>[Si<sub>8</sub>O<sub>20</sub>]F·8H<sub>2</sub>O from Akhaltsykhe localities are characterized by the deficiency of large cations K<sup>+</sup> and (NH<sub>4</sub>)<sup>+</sup> in the A site; the chemical composition of Talnakh sample (K<sub>0.94</sub>(NH<sub>4</sub>)<sub>0.06</sub>)<sub>Σ1.00</sub> Ca<sub>4</sub>[Si<sub>8</sub>O<sub>20</sub>]F·8H<sub>2</sub>O is close to the stoichiometric one. The large cations deficiency in the structure of Nidym and Akhaltsykhe samples is compensated by the presence of medium-sized Na<sup>+</sup> cations, located 1.12–1.31 Å away from the A position. The planar coordination of Na is formed by four H<sub>2</sub>O molecules. The occurrence of ammonium ions is found for the Nidym and Talnakh samples and their concentrations are estimated from the IR spectra and structure refinement. Polarized infrared measurements performed for fluorapophyllite-(K) samples oriented along the <i>c</i>-axis reveal pleochroic behavior of the OH absorption bands. The observed pleochroism is explained in terms of absorption from two OH vectors of the H<sub>2</sub>O molecules in the crystal structure.</p></div>\",\"PeriodicalId\":20132,\"journal\":{\"name\":\"Physics and Chemistry of Minerals\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2023-02-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physics and Chemistry of Minerals\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s00269-022-01229-y\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics and Chemistry of Minerals","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1007/s00269-022-01229-y","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Single-crystal X-ray diffraction and IR-spectroscopy studies of potassium-deficient fluorapophyllite-(K)
Three samples of fluorapophyllite-(K) with different cation composition were studied by the X-ray diffraction and IR-spectroscopy methods. The samples (K0.72(NH4)0.20)Σ0.92Na0.08 Ca4[Al0.04Si7.96O20]F·8H2O from Nidym and K0.87Na0.06 Ca4[Si8O20]F·8H2O from Akhaltsykhe localities are characterized by the deficiency of large cations K+ and (NH4)+ in the A site; the chemical composition of Talnakh sample (K0.94(NH4)0.06)Σ1.00 Ca4[Si8O20]F·8H2O is close to the stoichiometric one. The large cations deficiency in the structure of Nidym and Akhaltsykhe samples is compensated by the presence of medium-sized Na+ cations, located 1.12–1.31 Å away from the A position. The planar coordination of Na is formed by four H2O molecules. The occurrence of ammonium ions is found for the Nidym and Talnakh samples and their concentrations are estimated from the IR spectra and structure refinement. Polarized infrared measurements performed for fluorapophyllite-(K) samples oriented along the c-axis reveal pleochroic behavior of the OH absorption bands. The observed pleochroism is explained in terms of absorption from two OH vectors of the H2O molecules in the crystal structure.
期刊介绍:
Physics and Chemistry of Minerals is an international journal devoted to publishing articles and short communications of physical or chemical studies on minerals or solids related to minerals. The aim of the journal is to support competent interdisciplinary work in mineralogy and physics or chemistry. Particular emphasis is placed on applications of modern techniques or new theories and models to interpret atomic structures and physical or chemical properties of minerals. Some subjects of interest are:
-Relationships between atomic structure and crystalline state (structures of various states, crystal energies, crystal growth, thermodynamic studies, phase transformations, solid solution, exsolution phenomena, etc.)
-General solid state spectroscopy (ultraviolet, visible, infrared, Raman, ESCA, luminescence, X-ray, electron paramagnetic resonance, nuclear magnetic resonance, gamma ray resonance, etc.)
-Experimental and theoretical analysis of chemical bonding in minerals (application of crystal field, molecular orbital, band theories, etc.)
-Physical properties (magnetic, mechanical, electric, optical, thermodynamic, etc.)
-Relations between thermal expansion, compressibility, elastic constants, and fundamental properties of atomic structure, particularly as applied to geophysical problems
-Electron microscopy in support of physical and chemical studies
-Computational methods in the study of the structure and properties of minerals
-Mineral surfaces (experimental methods, structure and properties)