001047034 001__ 1047034
001047034 005__ 20251009202054.0
001047034 037__ $$aFZJ-2025-04085
001047034 1001_ $$0P:(DE-Juel1)130504$$aAngst, M.$$b0$$ufzj
001047034 1112_ $$aJCNS Workshop 2025, Trends and Perspectives in Neutron Scattering. Quantum Materials: Theory and Experiments$$cEvangelische Akademie Tutzing$$d2025-10-07 - 2025-10-09$$wGermany
001047034 245__ $$aCoupled charge, orbital, and spin degrees of freedom in geometricallyfrustrated YFe2O4
001047034 260__ $$c2025
001047034 3367_ $$033$$2EndNote$$aConference Paper
001047034 3367_ $$2DataCite$$aOther
001047034 3367_ $$2BibTeX$$aINPROCEEDINGS
001047034 3367_ $$2DRIVER$$aconferenceObject
001047034 3367_ $$2ORCID$$aLECTURE_SPEECH
001047034 3367_ $$0PUB:(DE-HGF)6$$2PUB:(DE-HGF)$$aConference Presentation$$bconf$$mconf$$s1759989462_5775$$xInvited
001047034 520__ $$aRhombohedral rare earth ferrites RFe2O4 have a strong tendency for coupled charge (Fe2+/3+) andspin order, despite the strong geometrical frustration of the interactions [1]. For R=Lu or Yb correspondingsuperstructure reflections or diffuse scattering appear at ( 1313 ℓ). However, the size of Y3+is considerably larger, with calculations [2] suggesting smaller in-plane propagation such as ( 1414 ).Here, we focus on single-crystal x-ray diffraction performed on highly stoichiometric single crystals[3] of YFe2O4. Magnetization vs T indicates two subsequent highly hysteretic magnetic transitions,separating a low-temperature (LT), an intermediate (IT), and a high-temperature (paramagnetic, HT)phase. XRD shows that these transitions are structural as well. In the HT phase, diffuse scatteringat ( 1313 ℓ) is similar to other rare earth ferrites. However, cooling into the magnetic phases, sharpsuperstructure reflections at different positions appear, with propagation ( 272737 ) in IT and ( 141434 ) inLT. We refined the superstructure in both phases and applied bond-valence-sum (BVS) analysis toprobe the charge order [4].In the LT phase, the structure is refined in P-1, with the inversion center between the two Fe layers.The BVS indicates a full charge order, with two of the Fe sites having valence close to 2+ and theother two close to 3+. Although of ( 1414 )-type, the arrangement of the valences differs from the predictionin [2]. Structural distortions also suggest (ferro) orbital order of the Fe2+ sites.The IT phase is also refined in P1. A clear splitting of one Y indicates the presence of disorder,which is likely connected to a fragile nature of this phase, which was not theoretically predicted. Ofthe 7 Fe sites, BVS shows 3 to have valences very close to 2+, indicating a strong localization of 3electrons on these sites. However, the BVS of one of the sites is about 2.5, and for the remainingsites also further away from the ideal 3 (BVS~2.8). Thus the localization of electrons in the IT phaseis incomplete, and it must be a dynamic situation with electron hopping occurring.[1] M. Angst, Physica Status Solidi RRL, 7, 383 (2013).[2] M. Naka, A. Nagano, and S. Ishihara, Phys. Rev. B, 77, 224441 (2008).[3] Th. Mueller, J. de Groot, J. Strempfer, and M. Angst, J. Crystal Growth, 428, 40 (2015).[4] Th. Mueller and M. Angst, submitted to PRB.
001047034 536__ $$0G:(DE-HGF)POF4-632$$a632 - Materials – Quantum, Complex and Functional Materials (POF4-632)$$cPOF4-632$$fPOF IV$$x0
001047034 536__ $$0G:(DE-HGF)POF4-6G4$$a6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4)$$cPOF4-6G4$$fPOF IV$$x1
001047034 7001_ $$0P:(DE-Juel1)156453$$aMüller, Thomas$$b1
001047034 909CO $$ooai:juser.fz-juelich.de:1047034$$pVDB
001047034 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)130504$$aForschungszentrum Jülich$$b0$$kFZJ
001047034 9131_ $$0G:(DE-HGF)POF4-632$$1G:(DE-HGF)POF4-630$$2G:(DE-HGF)POF4-600$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$aDE-HGF$$bForschungsbereich Materie$$lVon Materie zu Materialien und Leben$$vMaterials – Quantum, Complex and Functional Materials$$x0
001047034 9131_ $$0G:(DE-HGF)POF4-6G4$$1G:(DE-HGF)POF4-6G0$$2G:(DE-HGF)POF4-600$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$aDE-HGF$$bForschungsbereich Materie$$lGroßgeräte: Materie$$vJülich Centre for Neutron Research (JCNS) (FZJ)$$x1
001047034 9141_ $$y2025
001047034 9201_ $$0I:(DE-Juel1)JCNS-2-20110106$$kJCNS-2$$lStreumethoden$$x0
001047034 9201_ $$0I:(DE-82)080009_20140620$$kJARA-FIT$$lJARA-FIT$$x1
001047034 9201_ $$0I:(DE-Juel1)JCNS-4-20201012$$kJCNS-4$$lJCNS-4$$x2
001047034 980__ $$aconf
001047034 980__ $$aVDB
001047034 980__ $$aI:(DE-Juel1)JCNS-2-20110106
001047034 980__ $$aI:(DE-82)080009_20140620
001047034 980__ $$aI:(DE-Juel1)JCNS-4-20201012
001047034 980__ $$aUNRESTRICTED