{"id":154,"date":"2014-08-01T15:35:23","date_gmt":"2014-08-01T15:35:23","guid":{"rendered":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/?page_id=154"},"modified":"2016-08-11T10:19:41","modified_gmt":"2016-08-11T10:19:41","slug":"carbon","status":"publish","type":"page","link":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/reference\/carbon\/","title":{"rendered":"Carbon"},"content":{"rendered":"<p>Carbon, in its many forms may exhibit full sp2 or sp3 hybridisation, or a combination. \u00a0Equally it may be bound to O, S, N, metals in different ratios or be present as a carbide phase. \u00a0In fact the majority of samples exposed to the atmosphere will have a considerable concentration of carbon contamination ~ 2 nm thick.<\/p>\n<p>Common carbon, C(1s) reference energies:<\/p>\n<p>Adventitious Carbon: \u00a0284.8 eV (C-C and C-H bonds).<\/p>\n<ul>\n<li>Typically there will be some C-O and C=O structure associated (286 &#8211; 288 eV), however depending no the nature of the material, this is not always a good reference despite its wide use &#8211; for example carbide materials or for\u00a0aluminium, the carbon is typically around 286 eV.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"line-height: 1.5em\">Organic\/Polymeric materials \u00a0(these are average values &#8211; See reference [1]):<\/span><\/p>\n<ul>\n<li>C-C\/C-H \u00a0 \u00a0~ \u00a0285.0 eV<\/li>\n<li>C-O \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0~ \u00a0286.0 eV<\/li>\n<li>C=O \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 ~ 288 &#8211; 289 eV<\/li>\n<li>CF2 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0~ 292 eV<\/li>\n<li>CF3 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0~ 293 eV<\/li>\n<\/ul>\n<p>Inorganic carbon:<\/p>\n<ul>\n<li>Carbide ~282 &#8211; 283.5 eV<\/li>\n<li>Carbonates ~ 288 &#8211; 290 eV<\/li>\n<\/ul>\n<p>HOPG\/Graphite, Diamond, Graphene:<\/p>\n<ul>\n<li>SP2 carbon ~ 284.0 &#8211; 284.5 eV \u00a0(HOPG typically seen at 284.5 eV )<\/li>\n<li>SP3 carbon ~ 284.5 &#8211; 285.0 eV<\/li>\n<\/ul>\n<p>By far the best way of determining sp2\/sp3 ratio is by means of the D-value [2]. \u00a0By recording the carbon x-ray induced Auger peak and taking the maxima and minima from its differential form (figure 1), then the sp2%\u00a0may be found.<\/p>\n<figure class=\"image pull-left\">\n<figure class=\"image pull-left\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/files\/2014\/08\/merged_carbon_auger.jpg\" alt=\"Carbon Auger\" width=\"612\" height=\"377\" \/><figcaption class=\"caption\">Differentiated carbon Auger and D-Value plot for various carbons<\/figcaption><\/figure>\n<\/figure>\n<h5><\/h5>\n<h5>References<\/h5>\n<p>[1] \u00a0Beamson G, Briggs D. High Resolution XPS of Organic\u00a0Polymers &#8211; The Scienta ESCA 300 Database. John Wiley &amp; \u00a0Sons: Chichester, 1992.<\/p>\n<p>[2] J.C. Lascovich and S Scaglione,\u00a0<em>Appl. Surf. Sci.<\/em> 78 (1994) 17-24<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Carbon, in its many forms may exhibit full sp2 or sp3 hybridisation, or a combination. \u00a0Equally it may be bound to O, S, N, metals in different ratios or be present as a carbide phase. \u00a0In fact the majority of samples exposed to the atmosphere will have a considerable concentration of carbon contamination ~ 2<\/p>\n","protected":false},"author":829,"featured_media":0,"parent":147,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-154","page","type-page","status-publish","hentry"],"meta_box":[],"_links":{"self":[{"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/pages\/154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/users\/829"}],"replies":[{"embeddable":true,"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/comments?post=154"}],"version-history":[{"count":9,"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/pages\/154\/revisions"}],"predecessor-version":[{"id":372,"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/pages\/154\/revisions\/372"}],"up":[{"embeddable":true,"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/pages\/147"}],"wp:attachment":[{"href":"http:\/\/sites.cardiff.ac.uk\/xpsaccess\/wp-json\/wp\/v2\/media?parent=154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}