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Vertical Interface Induced Dielectric Relaxation in Nanocomposite (BaTiO3)1-x:(Sm2O3)x Thin Films.

Li W, Zhang W, Wang L, Gu J, Chen A, Zhao R, Liang Y, Guo H, Tang R, Wang C, Jin K, Wang H, Yang H - Sci Rep (2015)

Bottom Line: Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities.However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain.The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films.

View Article: PubMed Central - PubMed

Affiliation: 1] College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China [2] College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.

ABSTRACT
Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities. However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain. In this work, because of the ordered interfaces and large interfacial area, heteroepitaxial (BaTiO3)1-x:(Sm2O3)x thin films have been fabricated and used as a model system to investigate the relationship between vertical interfaces and dielectric properties. Due to a relatively large strain generated at the interfaces, vertical interfaces between BaTiO3 and Sm2O3 are revealed to become the sinks to attract oxygen vacancies. The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films. This work represents an approach to further understand that how interfaces influence on dielectric properties in oxide thin films.

No MeSH data available.


Related in: MedlinePlus

Variation of  as a function of temperature for BTO:Sm2O3 thin films with (a) x = 0.5 and (c) x = 0.62 measured at different frequencies. The corresponding Arrhenius plots of the frequency against temperature were shown in (b) and (d), respectively. The solid curves are the best fits to the Arrhenius law.
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f5: Variation of as a function of temperature for BTO:Sm2O3 thin films with (a) x = 0.5 and (c) x = 0.62 measured at different frequencies. The corresponding Arrhenius plots of the frequency against temperature were shown in (b) and (d), respectively. The solid curves are the best fits to the Arrhenius law.

Mentions: To further understand the physical process of the observed dielectric relaxation in the BTO:Sm2O3 thin films, the imaginary () part of electric modulus () given by M "= as a function of temperature at a series of frequencies were illustrated in Fig. 5(a). As we expected, well-defined M "(T ) peaks have been found in the whole temperature range. The  ~ T curve shifts towards higher temperature with increasing frequency, indicating a typical relaxation nature. The Arrhenius plots for Ln (fmax) vs 103/T were also shown in Fig. 5(b). Accordingly, the relaxation parameters of and were deduced to be 0.54 eV and 4.85 × 108 Hz for x = 0.5, and 0.59 eV and 1.72 × 109 Hz for x = 0.62, respectively. The activation energy obtained from is almost the same as the calculated values from tanδ(T) (see insets of Fig. 4(a)), which further confirms that the fitting results are reasonable. It should be pointed out that, because the relaxation time (τ = 1/f) for and tanδ (T) follow the general rule of τtanδ > τM”3031, the pre-exponential factor deduced for is always one order of magnitude larger than that estimated from tanδ (T).


Vertical Interface Induced Dielectric Relaxation in Nanocomposite (BaTiO3)1-x:(Sm2O3)x Thin Films.

Li W, Zhang W, Wang L, Gu J, Chen A, Zhao R, Liang Y, Guo H, Tang R, Wang C, Jin K, Wang H, Yang H - Sci Rep (2015)

Variation of  as a function of temperature for BTO:Sm2O3 thin films with (a) x = 0.5 and (c) x = 0.62 measured at different frequencies. The corresponding Arrhenius plots of the frequency against temperature were shown in (b) and (d), respectively. The solid curves are the best fits to the Arrhenius law.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4462142&req=5

f5: Variation of as a function of temperature for BTO:Sm2O3 thin films with (a) x = 0.5 and (c) x = 0.62 measured at different frequencies. The corresponding Arrhenius plots of the frequency against temperature were shown in (b) and (d), respectively. The solid curves are the best fits to the Arrhenius law.
Mentions: To further understand the physical process of the observed dielectric relaxation in the BTO:Sm2O3 thin films, the imaginary () part of electric modulus () given by M "= as a function of temperature at a series of frequencies were illustrated in Fig. 5(a). As we expected, well-defined M "(T ) peaks have been found in the whole temperature range. The  ~ T curve shifts towards higher temperature with increasing frequency, indicating a typical relaxation nature. The Arrhenius plots for Ln (fmax) vs 103/T were also shown in Fig. 5(b). Accordingly, the relaxation parameters of and were deduced to be 0.54 eV and 4.85 × 108 Hz for x = 0.5, and 0.59 eV and 1.72 × 109 Hz for x = 0.62, respectively. The activation energy obtained from is almost the same as the calculated values from tanδ(T) (see insets of Fig. 4(a)), which further confirms that the fitting results are reasonable. It should be pointed out that, because the relaxation time (τ = 1/f) for and tanδ (T) follow the general rule of τtanδ > τM”3031, the pre-exponential factor deduced for is always one order of magnitude larger than that estimated from tanδ (T).

Bottom Line: Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities.However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain.The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films.

View Article: PubMed Central - PubMed

Affiliation: 1] College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China [2] College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.

ABSTRACT
Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities. However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain. In this work, because of the ordered interfaces and large interfacial area, heteroepitaxial (BaTiO3)1-x:(Sm2O3)x thin films have been fabricated and used as a model system to investigate the relationship between vertical interfaces and dielectric properties. Due to a relatively large strain generated at the interfaces, vertical interfaces between BaTiO3 and Sm2O3 are revealed to become the sinks to attract oxygen vacancies. The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films. This work represents an approach to further understand that how interfaces influence on dielectric properties in oxide thin films.

No MeSH data available.


Related in: MedlinePlus