@article{ ISI:000357856900006,
Author = {Ocenasek, J. and Lu, H. and Bark, C. W. and Eom, C. B. and Alcala, J.
   and Catalan, G. and Gruverman, A.},
Title = {{Nanomechanics of flexoelectric switching}},
Journal = {{PHYSICAL REVIEW B}},
Year = {{2015}},
Volume = {{92}},
Number = {{3}},
Month = {{JUL 14}},
Abstract = {{We examine the phenomenon of flexoelectric switching of polarization in
   ultrathin films of barium titanate induced by a tip of an atomic force
   microscope (AFM). The spatial distribution of the tip-induced
   flexoelectricity is computationally modeled both for perpendicular
   mechanical load (point measurements) and for sliding load (scanning
   measurements), and compared with experiments. We find that (i)
   perpendicular load does not lead to stable ferroelectric switching in
   contrast to the load applied in the sliding contact load regime, due to
   nontrivial differences between the strain distributions in both regimes:
   ferroelectric switching for the perpendicular load mode is impaired by a
   strain gradient inversion layer immediately underneath the AFM tip;
   while for the sliding load regime, domain inversion is unimpaired within
   a greater material volume subjected to larger values of the mechanically
   induced electric field that includes the region behind the sliding tip;
   (ii) beyond a relatively small value of an applied force, increasing
   mechanical pressure does not increase the flexoelectric field inside the
   film, but results instead in a growing volume of the region subjected to
   such field that aids domain nucleation processes; and (iii) the
   flexoelectric coefficients of the films are of the order of few nC/m,
   which is much smaller than for bulk BaTiO3 ceramics, indicating that
   there is a ``flexoelectric size effect{''} that mirrors the
   ferroelectric one.}},
DOI = {{10.1103/PhysRevB.92.035417}},
Article-Number = {{035417}},
ISSN = {{1098-0121}},
EISSN = {{1550-235X}},
ResearcherID-Numbers = {{Gruverman, Alexei/P-3537-2014
   Ocenasek, Jan/E-8446-2012
   Catalan, Gustau/D-3233-2015
   Eom, Chang-Beom/I-5567-2014}},
ORCID-Numbers = {{Gruverman, Alexei/0000-0003-0492-2750
   Ocenasek, Jan/0000-0003-3462-0673
   Catalan, Gustau/0000-0003-0214-4828
   }},
Unique-ID = {{ISI:000357856900006}},
}

{"_id":"J2yHrvRPf7cgbKgh7","bibbaseid":"ocenasek-lu-bark-eom-alcala-catalan-gruverman-nanomechanicsofflexoelectricswitching-2015","downloads":0,"creationDate":"2018-09-17T23:43:09.125Z","title":"Nanomechanics of flexoelectric switching","author_short":["Ocenasek, J.","Lu, H.","Bark, C. W.","Eom, C. B.","Alcala, J.","Catalan, G.","Gruverman, A."],"year":2015,"bibtype":"article","biburl":"http://oxide.engr.wisc.edu/newWebsite/papers/oxide.bib","bibdata":{"bibtype":"article","type":"article","author":[{"propositions":[],"lastnames":["Ocenasek"],"firstnames":["J."],"suffixes":[]},{"propositions":[],"lastnames":["Lu"],"firstnames":["H."],"suffixes":[]},{"propositions":[],"lastnames":["Bark"],"firstnames":["C.","W."],"suffixes":[]},{"propositions":[],"lastnames":["Eom"],"firstnames":["C.","B."],"suffixes":[]},{"propositions":[],"lastnames":["Alcala"],"firstnames":["J."],"suffixes":[]},{"propositions":[],"lastnames":["Catalan"],"firstnames":["G."],"suffixes":[]},{"propositions":[],"lastnames":["Gruverman"],"firstnames":["A."],"suffixes":[]}],"title":"Nanomechanics of flexoelectric switching","journal":"PHYSICAL REVIEW B","year":"2015","volume":"92","number":"3","month":"JUL 14","abstract":"We examine the phenomenon of flexoelectric switching of polarization in ultrathin films of barium titanate induced by a tip of an atomic force microscope (AFM). The spatial distribution of the tip-induced flexoelectricity is computationally modeled both for perpendicular mechanical load (point measurements) and for sliding load (scanning measurements), and compared with experiments. We find that (i) perpendicular load does not lead to stable ferroelectric switching in contrast to the load applied in the sliding contact load regime, due to nontrivial differences between the strain distributions in both regimes: ferroelectric switching for the perpendicular load mode is impaired by a strain gradient inversion layer immediately underneath the AFM tip; while for the sliding load regime, domain inversion is unimpaired within a greater material volume subjected to larger values of the mechanically induced electric field that includes the region behind the sliding tip; (ii) beyond a relatively small value of an applied force, increasing mechanical pressure does not increase the flexoelectric field inside the film, but results instead in a growing volume of the region subjected to such field that aids domain nucleation processes; and (iii) the flexoelectric coefficients of the films are of the order of few nC/m, which is much smaller than for bulk BaTiO3 ceramics, indicating that there is a ``flexoelectric size effect'' that mirrors the ferroelectric one.","doi":"10.1103/PhysRevB.92.035417","article-number":"035417","issn":"1098-0121","eissn":"1550-235X","researcherid-numbers":"Gruverman, Alexei/P-3537-2014 Ocenasek, Jan/E-8446-2012 Catalan, Gustau/D-3233-2015 Eom, Chang-Beom/I-5567-2014","orcid-numbers":"Gruverman, Alexei/0000-0003-0492-2750 Ocenasek, Jan/0000-0003-3462-0673 Catalan, Gustau/0000-0003-0214-4828 ","unique-id":"ISI:000357856900006","bibtex":"@article{ ISI:000357856900006,\nAuthor = {Ocenasek, J. and Lu, H. and Bark, C. W. and Eom, C. B. and Alcala, J.\n and Catalan, G. and Gruverman, A.},\nTitle = {{Nanomechanics of flexoelectric switching}},\nJournal = {{PHYSICAL REVIEW B}},\nYear = {{2015}},\nVolume = {{92}},\nNumber = {{3}},\nMonth = {{JUL 14}},\nAbstract = {{We examine the phenomenon of flexoelectric switching of polarization in\n ultrathin films of barium titanate induced by a tip of an atomic force\n microscope (AFM). The spatial distribution of the tip-induced\n flexoelectricity is computationally modeled both for perpendicular\n mechanical load (point measurements) and for sliding load (scanning\n measurements), and compared with experiments. We find that (i)\n perpendicular load does not lead to stable ferroelectric switching in\n contrast to the load applied in the sliding contact load regime, due to\n nontrivial differences between the strain distributions in both regimes:\n ferroelectric switching for the perpendicular load mode is impaired by a\n strain gradient inversion layer immediately underneath the AFM tip;\n while for the sliding load regime, domain inversion is unimpaired within\n a greater material volume subjected to larger values of the mechanically\n induced electric field that includes the region behind the sliding tip;\n (ii) beyond a relatively small value of an applied force, increasing\n mechanical pressure does not increase the flexoelectric field inside the\n film, but results instead in a growing volume of the region subjected to\n such field that aids domain nucleation processes; and (iii) the\n flexoelectric coefficients of the films are of the order of few nC/m,\n which is much smaller than for bulk BaTiO3 ceramics, indicating that\n there is a ``flexoelectric size effect{''} that mirrors the\n ferroelectric one.}},\nDOI = {{10.1103/PhysRevB.92.035417}},\nArticle-Number = {{035417}},\nISSN = {{1098-0121}},\nEISSN = {{1550-235X}},\nResearcherID-Numbers = {{Gruverman, Alexei/P-3537-2014\n Ocenasek, Jan/E-8446-2012\n Catalan, Gustau/D-3233-2015\n Eom, Chang-Beom/I-5567-2014}},\nORCID-Numbers = {{Gruverman, Alexei/0000-0003-0492-2750\n Ocenasek, Jan/0000-0003-3462-0673\n Catalan, Gustau/0000-0003-0214-4828\n }},\nUnique-ID = {{ISI:000357856900006}},\n}\n\n","author_short":["Ocenasek, J.","Lu, H.","Bark, C. W.","Eom, C. B.","Alcala, J.","Catalan, G.","Gruverman, A."],"key":"ISI:000357856900006","id":"ISI:000357856900006","bibbaseid":"ocenasek-lu-bark-eom-alcala-catalan-gruverman-nanomechanicsofflexoelectricswitching-2015","role":"author","urls":{},"downloads":0,"html":""},"search_terms":["nanomechanics","flexoelectric","switching","ocenasek","lu","bark","eom","alcala","catalan","gruverman"],"keywords":[],"authorIDs":[],"dataSources":["zArY7xMz8KdDswhhx"]}