resumo
We report an effect of giant surface modification of a 5.6 nm thick BaTiO3 film grown on Si (100) substrate under poling by conductive tip of a scanning probe microscope (SPM). The surface can be locally elevated by about 9 nm under -20 V applied during scanning, resulting in the maximum strain of 160%. The threshold voltage for the surface modification is about 12 V. The modified topography is stable enough with time and slowly decays after poling with the rate similar to 0.02 nm/min. Strong vertical piezoresponse after poling is observed, too. Combined measurements by SPM and piezoresponse force microscopy (PFM) prove that the poled material develops high ferroelectric polarization that cannot be switched back even under an oppositely oriented electric field. The topography modification is hypothesized to be due to a strong Joule heating and concomitant interface reaction between underlying Si and BaTiO3. The top layer is supposed to become ferroelectric as a result of local crystallization of amorphous BaTiO3. This work opens up new possibilities to form nanoscale ferroelectric structures useful for various applications.
palavras-chave
DIP-PEN NANOLITHOGRAPHY; THIN-FILMS; NANOIMPRINT LITHOGRAPHY; FABRICATION; DEPOSITION; NANOFABRICATION
categoria
Materials Science
autores
Vaghefi, PM; Baghizadeh, A; Lourenco, AACS; Amaral, VS; Kholkin, AL
nossos autores
Ali Baghi Zadeh
Bolseiro de pós-Doutoramento
Andrei Kholkin
Investigador Jubilado
Armando António Cardoso Dos Santos Lourenço
Professor Auxiliar
Pegah Mirzadeh Vaghefi
Bolseiro de pós-Doutoramento
Vitor Brás Sequeira Amaral
Professor CatedráticoProjectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
MULTIFOX: Nanometric Probing and Modification of Multiferroic Oxides (PTDC/FIS/105416/2008)
Multiferroics and magnetoelectrics for spintronics: barriers and interfaces (PTDC/CTM/099415/2008)
RMNE-UA-National Network of Electron Microscopy (REDE/1509/RME/2005 )
agradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. We would like to thank the financial support from the FCT project PTDC/FIS/105416/2008 MULTIFOX and PTDC/CTM/099415/2008 grants and FCT project REDE/1509/RME/2005 to access all microscopes in pole of electron microscopy in Aveiro University.