{"title":"由电阻率测量得到的3-5 GPa Fe-Si合金相图","authors":"Meryem Berrada, Richard A. Secco","doi":"10.1007/s00269-022-01220-7","DOIUrl":null,"url":null,"abstract":"<div><p>One of the most extensively investigated properties of Fe is electrical resistivity (<i>ρ</i>) which features several well-established temperature (<i>T</i>) dependent characteristics. Based on systematic data for Fe and Fe–Si alloys and guidance from the 1 atm diagram, the <i>T-X</i> (composition <i>X</i>) phase diagram can be obtained at constant pressure (<i>P</i>) by plotting maps of constant <i>ρ</i> contours, proposed herein to be called ‘iso-ohms’, maps of constant <i>δρ/δT</i>, as well as maps of variations of exponent <i>x</i> in power law fits to <i>ρ(T</i><sup><i>x</i></sup><i>)</i>. Electrical resistivity measurements of Fe-(≤ 17wt%)Si alloys are available at 3–5 GPa and up to liquid temperatures. This study provides a new approach to mapping high <i>P</i>–<i>T</i> structural phase diagrams in the Fe-rich region of the Fe–Si system at moderate pressures and may be used for other compositions. Maps of iso-ohms suggest the α phase is the less resistive phase followed by <i>α</i><sub>2</sub>, <i>α</i><sub>1</sub>, η + α<sub>1</sub>, and ε + α<sub>1</sub>. Above ~ 11 wt% Si, the ε + α<sub>1</sub> displays a higher <i>ρ</i> than the liquid phase. This is discussed in terms of <i>s</i> and <i>d</i> electron scattering. Maps of constant <i>δρ/δT</i> emphasize the magnetic transition and boundary between the ε + α<sub>1</sub> and η + α<sub>1</sub> phases, while variations of exponent <i>x</i> outline the α<sub>2</sub> region. The Fe–Si system is of interest to the cores of the moon and Mercury.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-022-01220-7.pdf","citationCount":"0","resultStr":"{\"title\":\"Phase diagrams of Fe–Si alloys at 3–5 GPa from electrical resistivity measurements\",\"authors\":\"Meryem Berrada, Richard A. Secco\",\"doi\":\"10.1007/s00269-022-01220-7\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>One of the most extensively investigated properties of Fe is electrical resistivity (<i>ρ</i>) which features several well-established temperature (<i>T</i>) dependent characteristics. Based on systematic data for Fe and Fe–Si alloys and guidance from the 1 atm diagram, the <i>T-X</i> (composition <i>X</i>) phase diagram can be obtained at constant pressure (<i>P</i>) by plotting maps of constant <i>ρ</i> contours, proposed herein to be called ‘iso-ohms’, maps of constant <i>δρ/δT</i>, as well as maps of variations of exponent <i>x</i> in power law fits to <i>ρ(T</i><sup><i>x</i></sup><i>)</i>. Electrical resistivity measurements of Fe-(≤ 17wt%)Si alloys are available at 3–5 GPa and up to liquid temperatures. This study provides a new approach to mapping high <i>P</i>–<i>T</i> structural phase diagrams in the Fe-rich region of the Fe–Si system at moderate pressures and may be used for other compositions. Maps of iso-ohms suggest the α phase is the less resistive phase followed by <i>α</i><sub>2</sub>, <i>α</i><sub>1</sub>, η + α<sub>1</sub>, and ε + α<sub>1</sub>. Above ~ 11 wt% Si, the ε + α<sub>1</sub> displays a higher <i>ρ</i> than the liquid phase. This is discussed in terms of <i>s</i> and <i>d</i> electron scattering. Maps of constant <i>δρ/δT</i> emphasize the magnetic transition and boundary between the ε + α<sub>1</sub> and η + α<sub>1</sub> phases, while variations of exponent <i>x</i> outline the α<sub>2</sub> region. The Fe–Si system is of interest to the cores of the moon and Mercury.</p></div>\",\"PeriodicalId\":20132,\"journal\":{\"name\":\"Physics and Chemistry of Minerals\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2022-10-27\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://link.springer.com/content/pdf/10.1007/s00269-022-01220-7.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physics and Chemistry of Minerals\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s00269-022-01220-7\",\"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/s00269-022-01220-7","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}
Phase diagrams of Fe–Si alloys at 3–5 GPa from electrical resistivity measurements
One of the most extensively investigated properties of Fe is electrical resistivity (ρ) which features several well-established temperature (T) dependent characteristics. Based on systematic data for Fe and Fe–Si alloys and guidance from the 1 atm diagram, the T-X (composition X) phase diagram can be obtained at constant pressure (P) by plotting maps of constant ρ contours, proposed herein to be called ‘iso-ohms’, maps of constant δρ/δT, as well as maps of variations of exponent x in power law fits to ρ(Tx). Electrical resistivity measurements of Fe-(≤ 17wt%)Si alloys are available at 3–5 GPa and up to liquid temperatures. This study provides a new approach to mapping high P–T structural phase diagrams in the Fe-rich region of the Fe–Si system at moderate pressures and may be used for other compositions. Maps of iso-ohms suggest the α phase is the less resistive phase followed by α2, α1, η + α1, and ε + α1. Above ~ 11 wt% Si, the ε + α1 displays a higher ρ than the liquid phase. This is discussed in terms of s and d electron scattering. Maps of constant δρ/δT emphasize the magnetic transition and boundary between the ε + α1 and η + α1 phases, while variations of exponent x outline the α2 region. The Fe–Si system is of interest to the cores of the moon and Mercury.
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)