{"id":157,"date":"2017-08-08T20:50:07","date_gmt":"2017-08-08T20:50:07","guid":{"rendered":"https:\/\/home.physics.wisc.edu\/gilbert2\/?page_id=157"},"modified":"2026-03-09T02:30:03","modified_gmt":"2026-03-09T02:30:03","slug":"spectromicroscopy","status":"publish","type":"page","link":"https:\/\/home.physics.wisc.edu\/gilbert\/spectromicroscopy\/","title":{"rendered":"Spectromicroscopy"},"content":{"rendered":"

Spectromicroscopy<\/h1>
X-ray spectromicroscopes combine the advantages of x-ray spectroscopy and x-ray microscopy in a single device. X-ray absorption spectroscopy is sensitive to elemental composition and oxidation state, and requires a source of tunable x-rays – synchrotron radiation. There a number of way of imaging with x-rays, and performing laterally resolved spectroscopy.\r\n\r\nThe SPHINX and MEPHISTO instruments used by our group are X-ray PhotoElectron Emission spectroMicroscopes – X-PEEM. SPHINX (Spectromicroscope for PHotoelectron Imaging of Nanostructures with X-rays) Elmitec PEEM III and MEPHISTO (Microscope a Emission de PHoto_lectron par Illumination Synchrotronique de Type Onduleur).\r\n\r\nThe X-PEEM forms magnified images of a specimen surface by collecting and focussing photoelectrons. The field of electron imaging with electrostatic lenses was pioneered by Gert Rempfer (UV-PEEM), Brian Tonner (X-PEEM) and Ernst Bauer (LEEM) The lateral resolution does not reach that of electron microscopy because of lensing aberrations, but is presently better than 20 nm for MEPHISTO and 6 nm for SPHINX.\r\n\r\nThe spectromicroscopes use electrostatic or magnetic lenses to form a photoelectron image at the detector (see links above for specifics). The sample is held at a high negative voltage, while the first element is grounded, resulting in a strongly accelerating electric field between the sample and the optics. The detector is a multichannel plate that amplifies the electron signal, followed by a phosphor screen that provides the light image that is recorded by a video camera.\r\n\r\nNote that there is no energy filtering of the photoelectrons – the total electron yield of electrons is captured by the X-PEEM. The electron yield is proportional to the x-ray absorption cross section. The transmission of the optics is most efficient for the low energy (1-5 eV) secondary electrons that result from inelastic scattering of primary and Auger electrons within a surface layer of 50 – 100 \u00c5.\r\n

MEPHISTO<\/h2>\r\n

\"\"<\/a> The MEPHISTO spectromicroscope uses three electrostatic lenses to form a photoelectron image at the detector (see figure<\/i>). The sample is held at -10 to -20 kV while the first element is grounded, resulting in a strongly accelerating electric field between the sample and the optics. Each lens has three components, two grounded and the inner one held at -10 to -15 kV. The detector is a multichannel plate to ampify the electron signal, followed by a phosphor screen to provide the light image that is recorded by a video camera.<\/p><\/div><\/div>

SPHINX<\/h2>\r\nThe SPHINX spectromicroscope uses six magnetic lenses, as well as stigmators to form a photoelectron image at the detector. The sample is held at -20 kV, while the first element is grounded, resulting in a strongly accelerating electric field between the sample and the optics. The detector is a multichannel plate that amplifies the electron signal, followed by a phosphor screen that provides the light image that is recorded by a video camera. The SPHINX achieves a better performance than MEPHISTO (1.5-fold higher electron transmission, and 5.5 nm resolution).\r\n

PEEM-3<\/h2>\r\nFor a description of the PEEM-3 microscope, see here<\/a>.<\/div><\/div><\/div><\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"

X-ray spectromicroscopes combine the advantages of x-ray spectroscopy and x-ray microscopy in a single device. X-ray absorption spectroscopy is sensitive to elemental composition and oxidation state, and requires a source of tunable x-rays – synchrotron radiation. There a number of way of imaging with x-rays, and performing laterally resolved spectroscopy. The SPHINX and MEPHISTO instruments…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_uw_migration_status":"in-progress","_uw_gutenberg_post_content_before_migration":"","footnotes":""},"class_list":["post-157","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/pages\/157","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/comments?post=157"}],"version-history":[{"count":6,"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/pages\/157\/revisions"}],"predecessor-version":[{"id":1197,"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/pages\/157\/revisions\/1197"}],"wp:attachment":[{"href":"https:\/\/home.physics.wisc.edu\/gilbert\/wp-json\/wp\/v2\/media?parent=157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}