000056721 001__ 56721 000056721 005__ 20161006102718.0 000056721 0247_ $$2doi$$a10.1021/acs.nanolett.5b04455 000056721 0248_ $$2sideral$$a94469 000056721 037__ $$aART-2016-94469 000056721 041__ $$aeng 000056721 100__ $$0(orcid)0000-0003-0885-9541$$aGuzmán Aluja, Roger 000056721 245__ $$aPolar-Graded Multiferroic SrMnO3 Thin Films 000056721 260__ $$c2016 000056721 5060_ $$aAccess copy available to the general public$$fUnrestricted 000056721 5203_ $$aEngineering defects and strains in oxides provides a promising route for the quest of thin film materials with coexisting ferroic orders, multiferroics, with efficient magnetoelectric coupling at room temperature. Precise control of the strain gradient would enable custom tailoring of the multiferroic properties but presently remains challenging. Here we explore the existence of a polar-graded state in epitaxially strained antiferromagnetic SrMnO3 thin films, whose polar nature was predicted theoretically and recently demonstrated experimentally. By means of aberration-corrected scanning transmission electron microscopy we map the polar rotation of the ferroelectric polarization with atomic resolution, both far from and near the domain walls, and find flexoelectricity resulting from vertical strain gradients. The origin of this particular strain state is a gradual distribution of oxygen vacancies across the film thickness, according to electron energy loss spectroscopy. Herein we present a chemistry-mediated route to induce polar rotations in oxygen-deficient multiferroic films, resulting in flexoelectric polar rotations and with potentially enhanced piezoelectricity. 000056721 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/MAT2014-51982-C2$$9info:eu-repo/grantAgreement/EUR/FP7/312483-ESTEEM2$$9info:eu-repo/grantAgreement/EUR/FP7/ERC-StG-239739-STEMOX$$9info:eu-repo/grantAgreement/ES/DGA/E26-304043 000056721 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc$$uhttp://creativecommons.org/licenses/by-nc/3.0/es/ 000056721 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000056721 700__ $$0(orcid)0000-0002-6487-1505$$aMaurel Velázquez, Laura$$uUniversidad de Zaragoza 000056721 700__ $$0(orcid)0000-0002-6944-4713$$aLangenberg Pérez, Eric 000056721 700__ $$aLupini, Andrew R. 000056721 700__ $$0(orcid)0000-0002-4698-3378$$aAlgarabel Lafuente, Pedro Antonio$$uUniversidad de Zaragoza 000056721 700__ $$0(orcid)0000-0002-0111-8284$$aPardo Gracia, José Angel$$uUniversidad de Zaragoza 000056721 700__ $$0(orcid)0000-0002-6761-6171$$aMagén Domínguez, Cesar$$uUniversidad de Zaragoza 000056721 7102_ $$12003$$2395$$aUniversidad de Zaragoza$$bDepartamento de Física de la Materia Condensada$$cFísica de la Materia Condensada 000056721 7102_ $$15001$$2065$$aUniversidad de Zaragoza$$bDepartamento de Ciencia y Tecnología de Materiales y Fluidos$$cCiencia de los Materiales e Ingeniería Metalúrgica 000056721 773__ $$g16, 4 (2016), 2221-2227$$pNano lett.$$tNANO LETTERS$$x1530-6984 000056721 8564_ $$s3165569$$uhttp://zaguan.unizar.es/record/56721/files/texto_completo.pdf$$yPostprint 000056721 8564_ $$s71634$$uhttp://zaguan.unizar.es/record/56721/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000056721 909CO $$ooai:zaguan.unizar.es:56721$$particulos$$pdriver 000056721 951__ $$a2016-09-29-14:09:30 000056721 980__ $$aARTICLE