@prefix dcat: <http://www.w3.org/ns/dcat#> .
@prefix dct: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix vcard: <http://www.w3.org/2006/vcard/ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00861272v1> a dcat:Dataset ;
    dct:description """
              BaFe<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub> was recently prepared by hydrothermal synthesis and identified as the first two-dimensional (2D) Ising ferromagnetic oxide, in which honeycomb layers made up of edge-sharing FeO<sub>6</sub> octahedra containing high-spin Fe<sup>2+</sup> ions (<i>S</i> = 2) are isolated by PO<sub>4</sub> groups and Ba<sup>2+</sup> cations. BaFe<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub> has a trigonal <i>R</i>-3 structure at room temperature but adopts a triclinic <i>P</i>-1 structure below 140 K due to the Jahn-Teller (JT) instability arising from the (t<sub>2g</sub>)<sup>4</sup>(e<sub>g</sub>)<sup>2</sup> configuration. The triclinic crystal structure was refined to find significantly distorted Fe<sup>2+</sup>O<sub>6</sub> octahedra in the honeycomb layers while the distortion amplitude <i>Q</i><sub>JT</sub> was estimated to 0.019 Å. The JT stabilization energy is estimated to be 7 meV per formula unit by DFT calculations. Below 70 K, very close to the ferromagnetic transition temperature T<sub>c</sub> = 65.5 K, the structure of BaFe<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub> returns to a trigonal <i>R</i>-3 structure in the presence of significant ferromagnetic domains. This rare re-entrant structural transition is accompanied by a discontinuous change in the quadrupolar splitting of Fe<sup>2+</sup>, as determined by Mössbauer spectroscopy. EPR measurements show the presence of magnetic domains well above T<sub>c</sub> , as expected for a ferromagnetic 2D Ising system, and support that the magnetism of BaFe<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub> is uniaxial (g<sub>⊥</sub> = 0).
            """ ;
    dct:identifier "hal-00861272" ;
    dct:issued "2026-05-09T18:35:32.780944"^^xsd:dateTime ;
    dct:language "en" ;
    dct:modified "2026-05-09T18:35:32.780948"^^xsd:dateTime ;
    dct:publisher <https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> ;
    dct:title "Across the structural re-entrant transition in BaFe<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>: influence of the two-dimensional ferromagnetism" ;
    dcat:contactPoint [ a vcard:Organization ;
            vcard:fn "CCSD" ] ;
    dcat:distribution <https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00861272v1/resource/5aa7334c-bfb7-445b-82a2-7b7b20eed6a4> ;
    dcat:keyword "chemical-structure",
        "chimtheochemical-sciencestheoretical-andor-physical-chemistry",
        "crystal-structure",
        "infoeu-reposemanticsarticle",
        "journal-articles",
        "lattices",
        "magnetic-properties",
        "phase-transitions" ;
    dcat:landingPage <ISSN:%200002-7863> .

<ISSN:%200002-7863> a foaf:Document .

<https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-hal-00861272v1/resource/5aa7334c-bfb7-445b-82a2-7b7b20eed6a4> a dcat:Distribution ;
    dct:format "HTML" ;
    dct:issued "2026-05-09T18:35:32.782336"^^xsd:dateTime ;
    dct:modified "2026-05-09T18:35:32.772313"^^xsd:dateTime ;
    dct:title "Across the structural re-entrant transition in BaFe<sub>2</sub>(PO<sub>4</sub>)<sub>2</sub>: influence of the two-dimensional ferromagnetism" ;
    dcat:accessURL <https://hal.science/hal-00861272> .

<https://rec.harvest-normandie.data4citizen.com/organization/cce9db95-46d9-4dc2-84b6-764215d0a002> a foaf:Agent ;
    foaf:name "test_moissonnage_selune" .