Figshare最新文献

{"title":"Exploringnthe Links between Structural Distortions,nOrbital Ordering, and Multipolar Magnetic Ordering in Double PerovskitesnContaining Re(VI) and Os(VII)","authors":"Victor da Cruz Pinha Barbosa (11972929), Dalini D. Maharaj (3191052), Zachery W. Cronkright (20354296), Ye Wang (41998), Rong Cong (1411705), Erick Garcia (14440905), Arneil P. Reyes (2006617), Jiaqiang Yan (1396402), Clemens Ritter (1466062), Vesna F. Mitrović (9148159), Bruce D. Gaulin (3191043), John E. Greedan (1855921), Patrick M. Woodward (1619494)","doi":"10.1021/acs.chemmater.4c02135.s001","DOIUrl":"https://doi.org/10.1021/acs.chemmater.4c02135.s001","url":null,"abstract":"A combination of high-resolution powder diffraction techniquesnand solid-state NMR has been employed to explore the links betweenncrystal structure, orbital ordering, and magnetism in three isostructuralndouble perovskites containing transition metal ions with a 5d<sup>1</sup> configuration. In Ba<sub>2</sub>ZnReO<sub>6</sub>, both neutronnand synchrotron X-ray powder diffraction data reveal a cubic-to-tetragonalntransition at 23 K that breaks the degeneracy of the t<sub>2g</sub> orbitals and leads to a pattern of orbital ordering that stabilizesnmagnetic ordering when the sample is cooled below 16 K. Similar behaviornis observed in Ba<sub>2</sub>MgReO<sub>6</sub>, with an orbital orderingntemperature of 33 K and a magnetic ordering temperature of 18 K. Priorntheoretical works suggest that the pattern of orbital order seen innthe <i>P</i>4<sub>2</sub>/<i>mnm</i> space groupnis needed to stabilize the heavily canted antiferromagnetism of thesencompounds. Unfortunately, powder diffraction data is not sensitivenenough to differentiate between the <i>I</i>4/<i>mmm</i> and <i>P</i>4<sub>2</sub>/<i>mnm</i> structuralnmodels, as the distortions are too subtle to be unambiguously identifiednfrom either neutron or synchrotron X-ray powder diffraction methods.nIn contrast, both diffraction and <sup>7</sup>Li NMR data indicatenthat Ba<sub>2</sub>LiOsO<sub>6</sub> retains the cubic structure downnto 1.7 K. The antiferromagnetic ground state and lack of any signnof orbital ordering in Ba<sub>2</sub>LiOsO<sub>6</sub> provide compellingnevidence that the electronically driven tetragonal distortion seennin Ba<sub>2</sub>ZnReO<sub>6</sub>, and Ba<sub>2</sub>MgReO<sub>6</sub> is intimately linked to the magnetic ordering seen in those compounds.nThe absence of magnetic reflections in high intensity neutron powderndiffraction data collected on Ba<sub>2</sub>MgReO<sub>6</sub> stronglynsuggests ordering of multipolar moments on Re(VI), likely ferro-octupolarnordering.","PeriodicalId":522670,"journal":{"name":"Figshare","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147901487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}