{"title":"The nature of the air-cleaved mica surface","authors":"Hugo K. Christenson , Neil H. Thomson","doi":"10.1016/j.surfrep.2016.03.001","DOIUrl":null,"url":null,"abstract":"<div><p><span>The accepted image of muscovite mica is that of an inert and atomically smooth surface, easily prepared by cleavage in an ambient atmosphere. Consequently, mica is extensively used a model substrate in many fundamental studies of surface phenomena and as a substrate for AFM<span> imaging of biomolecules. In this review we present evidence from the literature that the above picture is not quite correct. The mica used in experimental work is almost invariably cleaved in laboratory air, where a reaction between the mica surface, atmospheric CO</span></span><sub>2</sub> and water occurs immediately after cleavage. The evidence suggests very strongly that as a result the mica surface becomes covered by up to one formula unit of K<sub>2</sub>CO<sub>3</sub> per nm<sup>2</sup>, which is mobile under humid conditions, and crystallises under drier conditions. The properties of mica in air or water vapour cannot be fully understood without reference to the surface K<sub>2</sub>CO<sub>3</sub><span>, and many studies of the structure of adsorbed water on mica surfaces may need to be revisited. With this new insight, however, the air-cleaved mica should provide exciting opportunities to study phenomena such as two-dimensional ion diffusion<span><span>, electrolyte effects on surface conductivity, and two-dimensional </span>crystal nucleation.</span></span></p></div>","PeriodicalId":434,"journal":{"name":"Surface Science Reports","volume":"71 2","pages":"Pages 367-390"},"PeriodicalIF":8.2000,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.surfrep.2016.03.001","citationCount":"98","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surface Science Reports","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167572916000066","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 98
Abstract
The accepted image of muscovite mica is that of an inert and atomically smooth surface, easily prepared by cleavage in an ambient atmosphere. Consequently, mica is extensively used a model substrate in many fundamental studies of surface phenomena and as a substrate for AFM imaging of biomolecules. In this review we present evidence from the literature that the above picture is not quite correct. The mica used in experimental work is almost invariably cleaved in laboratory air, where a reaction between the mica surface, atmospheric CO2 and water occurs immediately after cleavage. The evidence suggests very strongly that as a result the mica surface becomes covered by up to one formula unit of K2CO3 per nm2, which is mobile under humid conditions, and crystallises under drier conditions. The properties of mica in air or water vapour cannot be fully understood without reference to the surface K2CO3, and many studies of the structure of adsorbed water on mica surfaces may need to be revisited. With this new insight, however, the air-cleaved mica should provide exciting opportunities to study phenomena such as two-dimensional ion diffusion, electrolyte effects on surface conductivity, and two-dimensional crystal nucleation.
期刊介绍:
Surface Science Reports is a journal that specializes in invited review papers on experimental and theoretical studies in the physics, chemistry, and pioneering applications of surfaces, interfaces, and nanostructures. The topics covered in the journal aim to contribute to a better understanding of the fundamental phenomena that occur on surfaces and interfaces, as well as the application of this knowledge to the development of materials, processes, and devices. In this journal, the term "surfaces" encompasses all interfaces between solids, liquids, polymers, biomaterials, nanostructures, soft matter, gases, and vacuum. Additionally, the journal includes reviews of experimental techniques and methods used to characterize surfaces and surface processes, such as those based on the interactions of photons, electrons, and ions with surfaces.