| dbo:abstract |
Το εξαβορίδιο του σαμάριου (SmB6) είναι ένα υλικό το οποίο δρα πότε ως μονωτής σε ορισμένες μετρήσεις και πότε ως καλός αγωγός του ηλεκτρικού ρεύματος σε άλλες μετρήσεις. (el) Samariumhexaborid ist eine anorganische chemische Verbindung des Samariums und neben , SmB6 und dem instabilen Sm2B5 eines der bekannten Samariumboride. (de) Samarium hexaboride (SmB6) is an intermediate-valence compound where samarium is present both as Sm2+ and Sm3+ ions at the ratio 3:7. It belongs to a class of Kondo insulators. At temperatures above 50 K its properties are typical of a Kondo metal, with metallic electrical conductivity characterized by strong electron scattering, whereas at low temperatures, it behaves as a non-magnetic insulator with a narrow band gap of about 4–14 meV. The cooling-induced metal-insulator transition in SmB6 is accompanied by a sharp increase in thermal conductivity, peaking at about 15 K. The reason for this increase is that electrons do not contribute to thermal conductivity at low temperatures, which is instead dominated by phonons. The decrease in electron concentration reduced the rate of electron-phonon scattering. Some research claims that it may be a topological insulator. Other researchers found no evidence of topological surface states. The increasing electrical resistance with a reduction in temperature indicates that the material behaves as an insulator; however, recent measurements reveal a Fermi surface (an abstract boundary of electrons in momentum space) characteristic of a good metal, indicating a more exotic dual metal-insulating ground state. The electrical resistivity at temperatures below 4K displays a distinct plateau, which is thought to be the coexistence of an insulating state (bulk) and a conducting state (surface). At temperatures approaching absolute zero, the quantum oscillations of the material grow as the temperature declines, a behavior that contradicts both the Fermi analysis and the rules that govern conventional metals. While it has been argued that quantum oscillations on samples grown from aluminium flux may arise from aluminum inclusions, such an explanation is excluded for samples grown by the image furnace method rather than by the flux growth method. (en) 六硼化钐（化学式：SmB6）是钐的硼化物，为混合价态化合物，其中钐以Sm2+和Sm3+（3：7）离子的形式存在。它是Kondo绝缘体之一。在50 K（−223.2 °C）以上，它具有典型的Kondo金属特征，其金属导电性由强电子散射表征；而在低温下，它具有约4-14meV的窄带隙的非磁性绝缘特性。 (zh) Гексаборид самария — бинарное неорганическое соединениесамария и бора с формулой SmB6,кристаллы. (ru) |
| dbo:thumbnail |
wiki-commons:Special:FilePath/CaHexaboride.png?width=300 |
| dbo:wikiPageID |
37908591 (xsd:integer) |
| dbo:wikiPageLength |
8299 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID |
1066768035 (xsd:integer) |
| dbo:wikiPageWikiLink |
dbr:Samarium dbr:Topological_insulator dbc:Correlated_electrons dbr:Electron_scattering dbc:Samarium_compounds dbc:Borides dbr:Band_gap dbr:Kondo_insulator dbr:Thermal_conductivity dbr:Ions dbr:Absolute_zero dbr:Boride dbr:Phonon dbr:Fermi_surface dbr:Metal-insulator_transition |
| dbp:imagefile |
CaHexaboride.png (en) |
| dbp:wikiPageUsesTemplate |
dbt:Chembox dbt:Chembox_Hazards dbt:Chembox_Identifiers dbt:Chembox_Properties dbt:Reflist dbt:Samarium_compounds |
| dcterms:subject |
dbc:Correlated_electrons dbc:Samarium_compounds dbc:Borides |
| gold:hypernym |
dbr:Compound |
| rdf:type |
owl:Thing dul:ChemicalObject dbo:ChemicalSubstance wikidata:Q11173 yago:WikicatSamariumCompounds yago:Abstraction100002137 yago:Cognition100023271 yago:Compound105870180 yago:Concept105835747 yago:Content105809192 yago:Idea105833840 yago:PsychologicalFeature100023100 dbo:ChemicalCompound yago:Whole105869584 |
| rdfs:comment |
Το εξαβορίδιο του σαμάριου (SmB6) είναι ένα υλικό το οποίο δρα πότε ως μονωτής σε ορισμένες μετρήσεις και πότε ως καλός αγωγός του ηλεκτρικού ρεύματος σε άλλες μετρήσεις. (el) Samariumhexaborid ist eine anorganische chemische Verbindung des Samariums und neben , SmB6 und dem instabilen Sm2B5 eines der bekannten Samariumboride. (de) 六硼化钐（化学式：SmB6）是钐的硼化物，为混合价态化合物，其中钐以Sm2+和Sm3+（3：7）离子的形式存在。它是Kondo绝缘体之一。在50 K（−223.2 °C）以上，它具有典型的Kondo金属特征，其金属导电性由强电子散射表征；而在低温下，它具有约4-14meV的窄带隙的非磁性绝缘特性。 (zh) Гексаборид самария — бинарное неорганическое соединениесамария и бора с формулой SmB6,кристаллы. (ru) Samarium hexaboride (SmB6) is an intermediate-valence compound where samarium is present both as Sm2+ and Sm3+ ions at the ratio 3:7. It belongs to a class of Kondo insulators. At temperatures above 50 K its properties are typical of a Kondo metal, with metallic electrical conductivity characterized by strong electron scattering, whereas at low temperatures, it behaves as a non-magnetic insulator with a narrow band gap of about 4–14 meV. Some research claims that it may be a topological insulator. Other researchers found no evidence of topological surface states. (en) |
| rdfs:label |
Samariumhexaborid (de) Εξαβορίδιο του σαμάριου (el) Samarium hexaboride (en) Гексаборид самария (ru) 六硼化钐 (zh) |
| owl:sameAs |
freebase:Samarium hexaboride yago-res:Samarium hexaboride wikidata:Samarium hexaboride dbpedia-de:Samarium hexaboride dbpedia-el:Samarium hexaboride dbpedia-ru:Samarium hexaboride dbpedia-zh:Samarium hexaboride https://global.dbpedia.org/id/4uito |
| prov:wasDerivedFrom |
wikipedia-en:Samarium_hexaboride?oldid=1066768035&ns=0 |
| foaf:depiction |
wiki-commons:Special:FilePath/CaHexaboride.png |
| foaf:isPrimaryTopicOf |
wikipedia-en:Samarium_hexaboride |
| is dbo:wikiPageRedirects of |
dbr:Samarium_Hexaboride dbr:SmB6 dbr:Smb6 |
| is dbo:wikiPageWikiLink of |
dbr:Topological_insulator dbr:Hot_cathode dbr:Suchitra_Sebastian dbr:Kondo_insulator dbr:Piers_Coleman dbr:Samarium_Hexaboride dbr:SmB6 dbr:Smb6 |
| is foaf:primaryTopic of |
wikipedia-en:Samarium_hexaboride |
