Limits...
Visible-light-accelerated oxygen vacancy migration in strontium titanate.

Li Y, Lei Y, Shen BG, Sun JR - Sci Rep (2015)

Bottom Line: There is evidence that most of the attractive properties of SrTiO3 are closely associated with oxygen vacancies.Tuning the kinetics of oxygen vacancies is then highly desired.This effect provides a feasible approach towards the modulation of the anionic processes.

View Article: PubMed Central - PubMed

Affiliation: Beijing National Laboratory for Condensed Matter &Institute of Physics, Chinese Academy of Sciences, Beijing 100190, Peoples' Republic of China.

ABSTRACT
Strontium titanate is a model transition metal oxide that exhibits versatile properties of special interest for both fundamental and applied researches. There is evidence that most of the attractive properties of SrTiO3 are closely associated with oxygen vacancies. Tuning the kinetics of oxygen vacancies is then highly desired. Here we reported on a dramatic tuning of the electro-migration of oxygen vacancies by visible light illumination. It is found that, through depressing activation energy for vacancy diffusion, light illumination remarkably accelerates oxygen vacancies even at room temperature. This effect provides a feasible approach towards the modulation of the anionic processes. The principle proved here can be extended to other perovskite oxides, finding a wide application in oxide electronics.

No MeSH data available.


Related in: MedlinePlus

Concomitant variation in sheet conductance and structural deformation.(a) Evolution of the 002 reflection of STO with gating time, where VG = −300 V, P = 0 or 30 mW, and λ = 532 nm. (b) Lattice constant as a function of time, where VG = −300 V, P = 0 or 30 mW, and λ varies between 532 nm and 980 nm. (c) Sheet conductance of the LAO(3uc)/STO interface corresponding to the light ON/OFF operation, where P = 30 mW and λ varies between 532 nm and 980 nm. The applied current for resistive measurement is 1 μA. (d) A comparison of sheet conductance and structural change. Solid lines are guides for the eye. All measurements were performed at room temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4588568&req=5

f2: Concomitant variation in sheet conductance and structural deformation.(a) Evolution of the 002 reflection of STO with gating time, where VG = −300 V, P = 0 or 30 mW, and λ = 532 nm. (b) Lattice constant as a function of time, where VG = −300 V, P = 0 or 30 mW, and λ varies between 532 nm and 980 nm. (c) Sheet conductance of the LAO(3uc)/STO interface corresponding to the light ON/OFF operation, where P = 30 mW and λ varies between 532 nm and 980 nm. The applied current for resistive measurement is 1 μA. (d) A comparison of sheet conductance and structural change. Solid lines are guides for the eye. All measurements were performed at room temperature.

Mentions: To reveal the effect of light illumination, the evolution of the 002 reflection with time is recorded when STO is exposed to different lights in the presence of electrical bias. Figure 2a shows the XRD spectra for two typical cases of P = 0 and 30 mW (λ = 532 nm, VG = −300 V). Figure 2b is a summary of the data for different wavelengths (P = 30 mW). As shown in Fig. 2b, the acceleration of short wavelength light to gating effect is prompt: Lattice expansion occurs right upon the application of VG and completes within about 10 minutes. Increasing λ leads to an inclining of the c(t) curve, indicating a slowdown of the gating effect. To get a quantitative description of the wavelength effect, in Fig. 2c we present, in semi-logarithmic scale, the dependence of dc/dt on λ, derived from the c(t) curve in the initial stage of structural deformation. A simple calculation shows that dc/dt is ~0.0047 Å/min for λ = 532 nm and ~0.0001 Å/min for λ = 980 nm, depressing nearly 50-fold.


Visible-light-accelerated oxygen vacancy migration in strontium titanate.

Li Y, Lei Y, Shen BG, Sun JR - Sci Rep (2015)

Concomitant variation in sheet conductance and structural deformation.(a) Evolution of the 002 reflection of STO with gating time, where VG = −300 V, P = 0 or 30 mW, and λ = 532 nm. (b) Lattice constant as a function of time, where VG = −300 V, P = 0 or 30 mW, and λ varies between 532 nm and 980 nm. (c) Sheet conductance of the LAO(3uc)/STO interface corresponding to the light ON/OFF operation, where P = 30 mW and λ varies between 532 nm and 980 nm. The applied current for resistive measurement is 1 μA. (d) A comparison of sheet conductance and structural change. Solid lines are guides for the eye. All measurements were performed at room temperature.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588568&req=5

f2: Concomitant variation in sheet conductance and structural deformation.(a) Evolution of the 002 reflection of STO with gating time, where VG = −300 V, P = 0 or 30 mW, and λ = 532 nm. (b) Lattice constant as a function of time, where VG = −300 V, P = 0 or 30 mW, and λ varies between 532 nm and 980 nm. (c) Sheet conductance of the LAO(3uc)/STO interface corresponding to the light ON/OFF operation, where P = 30 mW and λ varies between 532 nm and 980 nm. The applied current for resistive measurement is 1 μA. (d) A comparison of sheet conductance and structural change. Solid lines are guides for the eye. All measurements were performed at room temperature.
Mentions: To reveal the effect of light illumination, the evolution of the 002 reflection with time is recorded when STO is exposed to different lights in the presence of electrical bias. Figure 2a shows the XRD spectra for two typical cases of P = 0 and 30 mW (λ = 532 nm, VG = −300 V). Figure 2b is a summary of the data for different wavelengths (P = 30 mW). As shown in Fig. 2b, the acceleration of short wavelength light to gating effect is prompt: Lattice expansion occurs right upon the application of VG and completes within about 10 minutes. Increasing λ leads to an inclining of the c(t) curve, indicating a slowdown of the gating effect. To get a quantitative description of the wavelength effect, in Fig. 2c we present, in semi-logarithmic scale, the dependence of dc/dt on λ, derived from the c(t) curve in the initial stage of structural deformation. A simple calculation shows that dc/dt is ~0.0047 Å/min for λ = 532 nm and ~0.0001 Å/min for λ = 980 nm, depressing nearly 50-fold.

Bottom Line: There is evidence that most of the attractive properties of SrTiO3 are closely associated with oxygen vacancies.Tuning the kinetics of oxygen vacancies is then highly desired.This effect provides a feasible approach towards the modulation of the anionic processes.

View Article: PubMed Central - PubMed

Affiliation: Beijing National Laboratory for Condensed Matter &Institute of Physics, Chinese Academy of Sciences, Beijing 100190, Peoples' Republic of China.

ABSTRACT
Strontium titanate is a model transition metal oxide that exhibits versatile properties of special interest for both fundamental and applied researches. There is evidence that most of the attractive properties of SrTiO3 are closely associated with oxygen vacancies. Tuning the kinetics of oxygen vacancies is then highly desired. Here we reported on a dramatic tuning of the electro-migration of oxygen vacancies by visible light illumination. It is found that, through depressing activation energy for vacancy diffusion, light illumination remarkably accelerates oxygen vacancies even at room temperature. This effect provides a feasible approach towards the modulation of the anionic processes. The principle proved here can be extended to other perovskite oxides, finding a wide application in oxide electronics.

No MeSH data available.


Related in: MedlinePlus