{"@context":{"@vocab":"https://cir.nii.ac.jp/schema/1.0/","rdfs":"http://www.w3.org/2000/01/rdf-schema#","dc":"http://purl.org/dc/elements/1.1/","dcterms":"http://purl.org/dc/terms/","foaf":"http://xmlns.com/foaf/0.1/","prism":"http://prismstandard.org/namespaces/basic/2.0/","cinii":"http://ci.nii.ac.jp/ns/1.0/","datacite":"https://schema.datacite.org/meta/kernel-4/","ndl":"http://ndl.go.jp/dcndl/terms/","jpcoar":"https://github.com/JPCOAR/schema/blob/master/2.0/"},"@id":"https://cir.nii.ac.jp/crid/1361699993490825728.json","@type":"Article","productIdentifier":[{"identifier":{"@type":"DOI","@value":"10.1093/gji/ggaa508"}},{"identifier":{"@type":"URI","@value":"http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa508/33993605/ggaa508.pdf"}},{"identifier":{"@type":"URI","@value":"http://academic.oup.com/gji/article-pdf/224/2/1256/34571623/ggaa508.pdf"}}],"dc:title":[{"@value":"High-coercivity magnetic minerals in archaeological baked clay and bricks"}],"description":[{"type":"abstract","notation":[{"@value":"<jats:title>SUMMARY</jats:title><jats:p>The thorough understanding of magnetic mineralogy is a prerequisite of any successful palaeomagnetic or archaeomagnetic study. Magnetic minerals in archaeological ceramics and baked clay may be inherited from the parent material or, more frequently, formed during the firing process. The resulting magnetic mineralogy may be complex, including ferrimagnetic phases not commonly encountered in rocks. Towards this end, we carried out a detailed rock magnetic study on a representative collection of archaeological ceramics (baked clay from combustion structures and bricks) from Bulgaria and Russia. Experiments included measurement of isothermal remanence acquisition and demagnetization as a function of temperature between 20 and &gt;600 °C. For selected samples, low-temperature measurements of saturation remanence and initial magnetic susceptibility between 1.8 and 300 K have been carried out. All studied samples contain a magnetically soft mineral identified as maghemite probably substituted by Ti, Mn and/or Al. Stoichiometric magnetite has never been observed, as evidenced by the absence of the Verwey phase transition. In addition, one or two magnetically hard mineral phases have been detected, differing sharply in their respective unblocking temperatures. One of these unblocking between 540 and 620 °C is believed to be substituted hematite. Another phase unblocks at much lower temperatures, between 140 and 240 °C, and its magnetic properties correspond to an enigmatic high coercivity, stable, low-unblocking temperature (HCSLT) phase reported earlier. In a few samples, high- and low unblocking temperature, magnetically hard phases appear to coexist; in the others, the HCSLT phase is the only magnetically hard mineral present.</jats:p>"}]}],"creator":[{"@id":"https://cir.nii.ac.jp/crid/1381699993490825734","@type":"Researcher","foaf:name":[{"@value":"Andrei Kosterov"}],"jpcoar:affiliationName":[{"@value":"St. Petersburg State University, St. Petersburg 199034, Russia"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825730","@type":"Researcher","foaf:name":[{"@value":"Mary Kovacheva"}],"jpcoar:affiliationName":[{"@value":"National Institute of Geophysics, Geodesy and Geography, Bulgarian Academy of Sciences, Sofia 1040, Bulgaria"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825728","@type":"Researcher","foaf:name":[{"@value":"Maria Kostadinova-Avramova"}],"jpcoar:affiliationName":[{"@value":"National Institute of Geophysics, Geodesy and Geography, Bulgarian Academy of Sciences, Sofia 1040, Bulgaria"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825731","@type":"Researcher","foaf:name":[{"@value":"Pavel Minaev"}],"jpcoar:affiliationName":[{"@value":"Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow 123995, Russia"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825729","@type":"Researcher","foaf:name":[{"@value":"Natalia Salnaia"}],"jpcoar:affiliationName":[{"@value":"Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow 123995, Russia"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825733","@type":"Researcher","foaf:name":[{"@value":"Leonid Surovitskii"}],"jpcoar:affiliationName":[{"@value":"St. Petersburg State University, St. Petersburg 199034, Russia"},{"@value":"Michigan Technological University, Houghton, MI 49931, USA"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825735","@type":"Researcher","foaf:name":[{"@value":"Svetlana Yanson"}],"jpcoar:affiliationName":[{"@value":"St. Petersburg State University, St. Petersburg 199034, Russia"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825732","@type":"Researcher","foaf:name":[{"@value":"Elena Sergienko"}],"jpcoar:affiliationName":[{"@value":"St. Petersburg State University, St. Petersburg 199034, Russia"}]},{"@id":"https://cir.nii.ac.jp/crid/1381699993490825736","@type":"Researcher","foaf:name":[{"@value":"Petr Kharitonskii"}],"jpcoar:affiliationName":[{"@value":"St. Petersburg Electrotechnical University “LETI”, St. Petersburg 197376, Russia"}]}],"publication":{"publicationIdentifier":[{"@type":"PISSN","@value":"0956540X"},{"@type":"EISSN","@value":"1365246X"}],"prism:publicationName":[{"@value":"Geophysical Journal International"}],"dc:publisher":[{"@value":"Oxford University Press (OUP)"}],"prism:publicationDate":"2020-10-23","prism:volume":"224","prism:number":"2","prism:startingPage":"1256","prism:endingPage":"1271"},"reviewed":"false","dc:rights":["https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model"],"url":[{"@id":"http://academic.oup.com/gji/advance-article-pdf/doi/10.1093/gji/ggaa508/33993605/ggaa508.pdf"},{"@id":"http://academic.oup.com/gji/article-pdf/224/2/1256/34571623/ggaa508.pdf"}],"createdAt":"2020-10-20","modifiedAt":"2023-10-10","relatedProduct":[{"@id":"https://cir.nii.ac.jp/crid/2050307417125247104","@type":"Article","resourceType":"学術雑誌論文(journal article)","relationType":["isReferencedBy"],"jpcoar:relatedTitle":[{"@value":"High spatial resolution magnetic mapping using ultra-high sensitivity scanning SQUID microscopy on a speleothem from the Kingdom of Tonga, southern Pacific"}]}],"dataSourceIdentifier":[{"@type":"CROSSREF","@value":"10.1093/gji/ggaa508"},{"@type":"CROSSREF","@value":"10.1186/s40623-021-01401-8_references_DOI_AB7W7dndlZURHjPWuIElkyqs1Fa"}]}