Lithuanian Journal of Physics article / Lietuvos fizikos žurnalo straipsnis

LOCAL PIEZOELECTRICITY IN SrTiO₃-BiTiO₃ CERAMICS
R. Grigalaitis^a, Š. Bagdzevičius^a, J. Banys^a, E.E. Tornau^b, K. Bormanis^c, A. Sternberg^c, I. Bdikin^d,e, and A. Kholkin^d
^aFaculty of Physics, Vilnius University, Saulėtekio 9, LT-10222 Vilnius, Lithuania
^bCenter for Physical Sciences and Technology, A. Goštauto 11, LT-01108 Vilnius, Lithuania
^cInstitute of Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga, Latvia
^dDepartment of Ceramics and Glass Engineering/CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
^eDepartment of Mechanical Engineering/TEMA, University of Aveiro, 3810-193 Aveiro, Portugal
E-mail: robertas.grigalaitis@ff.vu..lt

Received 5 June 2014; revised 14 July 2014; accepted 23 September 2014

Local piezoelectric properties of Bi-doped SrTiO₃ ceramics have been investigated by piezoresponse force microscopy. The appearance of both out-of-plane and in-plane polarization components confirmed the piezoelectric nature of the obtained signal. The absence of labyrinth-like structures in observed piezoelectric contrast is not consistent with the expected existence of a relaxor ferroelectric state in this material. The close similarity of local piezoelectric properties in Bi-doped SrTiO₃ with pure SrTiO₃ suggests that the origin of obtained piezoresponse can be attributed to the flexoelectric phenomenon. Bi-doping leads to occurrence of oxygen vacancies and negative charge on the surface of the sample.

Keywords: piezoelectric, piezoresponse force microscopy, flexoelectric, ferroelectric relaxor
PACS: 77.84.-s, 07.79.Lh, 77.65.Ly, 77.80.Jk

LOKALIOS PJEZOELEKTRINĖS SrTiO3-BiTiO3 KERAMIKŲ SAVYBĖS

R. Grigalaitis^a, Š. Bagdzevičius^a, J. Banys^a, E.E. Tornau^b, K. Bormanis^c, A. Sternberg^c, I. Bdikin^d,e, A. Kholkin^d
^aVilniaus universiteto Fizikos fakultetas, Vilnius, Lietuva
^bFizinių ir technologijos mokslų centras, Vilnius, Lietuva
^cLatvijos universiteto Kietojo kūno fizikos institutas, Ryga, Latvija
^dAveiro universiteto Keramikos ir stiklo inžinerijos fakultetas / CICECO, Aveiro, Portugalija
^eAveiro universiteto Mechaninės inžinerijos fakultetas / TEMA, Aveiro, Portugalija

Lokalios pjezoelektrinės bismutu praturtintų SrTiO₃ keramikų savybės buvo tyrinėjamos pjezoelektrinės jėgos mikroskopijos metodu. Pjezoelektrinę gautų duomenų prigimtį patvirtino tai, kad buvo stebimos tiek statmenosios, tiek ir lygiagrečiosios bandinio plokštumai poliarizacijos komponentės. Kadangi matuotasis pjezoelektrinis atsakas neparodė jokių „labirinto“ tipo struktūrų, prognozuotos feroelektrinio relaksoriaus būsenos šioje medžiagoje aptikti nepavyko. Ženklus lokalių pjezoelektrinių bismutu praturtintų SrTiO₃ keramikų savybių panašumas į grynos SrTiO₃ savybes leidžia daryti prielaidą, kad gautasis pjezoelektrinis atsakas gali būti priskirtas fleksoelektriniam efektui. Praturtinimas bismutu sukelia deguonies vakansijų bei neigiamo krūvio atsiradimą bandinio paviršiuje.

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