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Ferroelectric domain wall motion induced by polarized light.

Rubio-Marcos F, Del Campo A, Marchet P, Fernández JF - Nat Commun (2015)

Bottom Line: The motion of the associated domain walls provides the basis for ferroelectric memory, in which the storage of data bits is achieved by driving domain walls that separate regions with different polarization directions.Here we show the surprising ability to move ferroelectric domain walls of a BaTiO₃ single crystal by varying the polarization angle of a coherent light source.This effect potentially leads to the non-contact remote control of ferroelectric domain walls by light.

View Article: PubMed Central - PubMed

Affiliation: Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC, Kelsen 5, Madrid 28049, Spain.

ABSTRACT
Ferroelectric materials exhibit spontaneous and stable polarization, which can usually be reoriented by an applied external electric field. The electrically switchable nature of this polarization is at the core of various ferroelectric devices. The motion of the associated domain walls provides the basis for ferroelectric memory, in which the storage of data bits is achieved by driving domain walls that separate regions with different polarization directions. Here we show the surprising ability to move ferroelectric domain walls of a BaTiO₃ single crystal by varying the polarization angle of a coherent light source. This unexpected coupling between polarized light and ferroelectric polarization modifies the stress induced in the BaTiO₃ at the domain wall, which is observed using in situ confocal Raman spectroscopy. This effect potentially leads to the non-contact remote control of ferroelectric domain walls by light.

No MeSH data available.


Mapping of the domain structure of the BTO single crystal through confocal Raman microscopy:(a) optical micrograph of the BTO single crystal. The white rectangle of Fig. 1a shows the positions where the XY Raman image and XZ Raman depth scan image are performed and correspond with the area of previous AFM analysis. The Raman image shows the domain distribution at the surface by colour code (b) as well as in the depth scan, cross section, (c). The Raman images resulted from the mapping of the different single Raman spectra collected in each pixel of the marked rectangle area in a. Raman spectra having same spectral shift for the Raman modes are identified using the same colour. The intensity of the colour is correlated with the Raman intensity. Scale bar, 20 μm. (d) Main Raman spectra of BTO Raman image associated with the three different colours: red=a-domain, blue=c-domain, green=b-domain, which are collected in the points marked as A, C and B in (b) respectively. The numbers next to the vibrational peaks represent the main atomic motions (for the assignment of the Raman modes see Supplementary Table 2). The inserts show magnified Raman spectra, ascribed to the 4 and 5 Raman modes, respectively.
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f2: Mapping of the domain structure of the BTO single crystal through confocal Raman microscopy:(a) optical micrograph of the BTO single crystal. The white rectangle of Fig. 1a shows the positions where the XY Raman image and XZ Raman depth scan image are performed and correspond with the area of previous AFM analysis. The Raman image shows the domain distribution at the surface by colour code (b) as well as in the depth scan, cross section, (c). The Raman images resulted from the mapping of the different single Raman spectra collected in each pixel of the marked rectangle area in a. Raman spectra having same spectral shift for the Raman modes are identified using the same colour. The intensity of the colour is correlated with the Raman intensity. Scale bar, 20 μm. (d) Main Raman spectra of BTO Raman image associated with the three different colours: red=a-domain, blue=c-domain, green=b-domain, which are collected in the points marked as A, C and B in (b) respectively. The numbers next to the vibrational peaks represent the main atomic motions (for the assignment of the Raman modes see Supplementary Table 2). The inserts show magnified Raman spectra, ascribed to the 4 and 5 Raman modes, respectively.

Mentions: The AFM technique gives topographical information of the domain structure but yields no structural information. Recent methods based on confocal Raman microscopy (CRM), give the possibility to study at a local scale the structural deformations of perovskites, induced both by the tilting of BO6 octahedra and by the cationic displacements20. CRM is here combined with AFM in the same apparatus, thus giving direct correlations between topography and local structure. Figure 2a depicts an optical micrograph of the polished surface of the crystal, aligned perpendicularly to the Raman laser. The Raman spectra are collected at a plane located just below the surface of the sample, where the Raman intensity is maximized. The selected area (150 × 30 μm) is the one previously studied by AFM. The acquisition time for a single Raman spectrum was 1 s (1 pixel). Thus the Raman image consisting of 150 × 30 pixels (4,500 spectra) required 75 min for the planar section. Features such as Raman peak intensity, peak width or Raman shifts are fitted with algorithms to compare information and to represent the derived Raman image. The assignments of the observed Raman modes, both symmetry and nature (first and second order), are summarized in the Supplementary Table 2. Raman spectra having same Raman shift are classified by colours and the colour intensity corresponds to the Raman intensity. The combination of colours results in a Raman image of the surface (Fig. 2b) and a Raman depth scan image of the cross-section (Fig. 2c). Figure 2d shows the average Raman spectra obtained in adjacent domains: A (red) and C (blue) points.


Ferroelectric domain wall motion induced by polarized light.

Rubio-Marcos F, Del Campo A, Marchet P, Fernández JF - Nat Commun (2015)

Mapping of the domain structure of the BTO single crystal through confocal Raman microscopy:(a) optical micrograph of the BTO single crystal. The white rectangle of Fig. 1a shows the positions where the XY Raman image and XZ Raman depth scan image are performed and correspond with the area of previous AFM analysis. The Raman image shows the domain distribution at the surface by colour code (b) as well as in the depth scan, cross section, (c). The Raman images resulted from the mapping of the different single Raman spectra collected in each pixel of the marked rectangle area in a. Raman spectra having same spectral shift for the Raman modes are identified using the same colour. The intensity of the colour is correlated with the Raman intensity. Scale bar, 20 μm. (d) Main Raman spectra of BTO Raman image associated with the three different colours: red=a-domain, blue=c-domain, green=b-domain, which are collected in the points marked as A, C and B in (b) respectively. The numbers next to the vibrational peaks represent the main atomic motions (for the assignment of the Raman modes see Supplementary Table 2). The inserts show magnified Raman spectra, ascribed to the 4 and 5 Raman modes, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4382678&req=5

f2: Mapping of the domain structure of the BTO single crystal through confocal Raman microscopy:(a) optical micrograph of the BTO single crystal. The white rectangle of Fig. 1a shows the positions where the XY Raman image and XZ Raman depth scan image are performed and correspond with the area of previous AFM analysis. The Raman image shows the domain distribution at the surface by colour code (b) as well as in the depth scan, cross section, (c). The Raman images resulted from the mapping of the different single Raman spectra collected in each pixel of the marked rectangle area in a. Raman spectra having same spectral shift for the Raman modes are identified using the same colour. The intensity of the colour is correlated with the Raman intensity. Scale bar, 20 μm. (d) Main Raman spectra of BTO Raman image associated with the three different colours: red=a-domain, blue=c-domain, green=b-domain, which are collected in the points marked as A, C and B in (b) respectively. The numbers next to the vibrational peaks represent the main atomic motions (for the assignment of the Raman modes see Supplementary Table 2). The inserts show magnified Raman spectra, ascribed to the 4 and 5 Raman modes, respectively.
Mentions: The AFM technique gives topographical information of the domain structure but yields no structural information. Recent methods based on confocal Raman microscopy (CRM), give the possibility to study at a local scale the structural deformations of perovskites, induced both by the tilting of BO6 octahedra and by the cationic displacements20. CRM is here combined with AFM in the same apparatus, thus giving direct correlations between topography and local structure. Figure 2a depicts an optical micrograph of the polished surface of the crystal, aligned perpendicularly to the Raman laser. The Raman spectra are collected at a plane located just below the surface of the sample, where the Raman intensity is maximized. The selected area (150 × 30 μm) is the one previously studied by AFM. The acquisition time for a single Raman spectrum was 1 s (1 pixel). Thus the Raman image consisting of 150 × 30 pixels (4,500 spectra) required 75 min for the planar section. Features such as Raman peak intensity, peak width or Raman shifts are fitted with algorithms to compare information and to represent the derived Raman image. The assignments of the observed Raman modes, both symmetry and nature (first and second order), are summarized in the Supplementary Table 2. Raman spectra having same Raman shift are classified by colours and the colour intensity corresponds to the Raman intensity. The combination of colours results in a Raman image of the surface (Fig. 2b) and a Raman depth scan image of the cross-section (Fig. 2c). Figure 2d shows the average Raman spectra obtained in adjacent domains: A (red) and C (blue) points.

Bottom Line: The motion of the associated domain walls provides the basis for ferroelectric memory, in which the storage of data bits is achieved by driving domain walls that separate regions with different polarization directions.Here we show the surprising ability to move ferroelectric domain walls of a BaTiO₃ single crystal by varying the polarization angle of a coherent light source.This effect potentially leads to the non-contact remote control of ferroelectric domain walls by light.

View Article: PubMed Central - PubMed

Affiliation: Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC, Kelsen 5, Madrid 28049, Spain.

ABSTRACT
Ferroelectric materials exhibit spontaneous and stable polarization, which can usually be reoriented by an applied external electric field. The electrically switchable nature of this polarization is at the core of various ferroelectric devices. The motion of the associated domain walls provides the basis for ferroelectric memory, in which the storage of data bits is achieved by driving domain walls that separate regions with different polarization directions. Here we show the surprising ability to move ferroelectric domain walls of a BaTiO₃ single crystal by varying the polarization angle of a coherent light source. This unexpected coupling between polarized light and ferroelectric polarization modifies the stress induced in the BaTiO₃ at the domain wall, which is observed using in situ confocal Raman spectroscopy. This effect potentially leads to the non-contact remote control of ferroelectric domain walls by light.

No MeSH data available.