Through the VFT law, the Semaxanib concentration activation energy E a and the freezing temperature T can be obtained. Tau τ is probably determined by the as-deposited temperature. So, the related activation and Mizoribine order freezing temperature could be calculated afterwards. The cause of distribution of the relaxation times has been associated with certain particular factors, e.g., the suggestion made by Kliem and Arlt [24]

concerning the occurrence of protonic resonance and Cabeza et al. [25] concerning the porosity effect. Equally, dielectric relaxation of the PNZT samples can be modeled by the CD law as well. The inset of Figure 7 shows the relationship between the CD fitting parameters (beta and tau) and the grain size value likewise. The trend of beta rises from 12.1 nm, peaks at 22.5 nm with the beta value of 0.03, and then glides back downwards within the range of 22.5 to 25 nm. The beta value is therefore see more shown to represent the deteriorative degree of dielectric relaxation. In the same manner,

the trend of tau decreases from 12.1 to 25 nm. The trend of beta and tau for the PNZT samples is similar to the trends observed for the CeO2 samples. Conclusions The ALD CeO2 samples were grown as crystalline thin films for a range of substrate temperatures within the ALD growth window of the Ce[mmp]4 precursor, with water as an oxidant. XRD and Raman spectra show an increase in grain size for increasing growth temperatures. From the C-V measurement of the samples, strong frequency dispersion is observed. In order to further investigate the dielectric relaxation, the normalized dielectric constant is utilized for the CeO2 samples of different grain sizes. The CeO2 samples have better dielectric relaxation behavior after annealing since the annealed samples have a larger grain size. Within the grain size range of the CeO2 samples (6.13 to 23.62 nm), the most serious frequency Bay 11-7085 dependence of the k value is found in the sample of thickness 8.83 nm. A similar relationship between grain size and dielectric relaxation is also observed

in CCTO and Nd-doped PNZT samples. The mechanism of grain size effects is attributed to the alignment enhancement of the polar nanodomains. Authors’ information CZ is a PhD student in the University of Liverpool. CZZ is a professor in Xi’an Jiaotong-Liverpool University. MW is a research associate in the University of Liverpool. ST and PC are professors in the University of Liverpool. PK is a research fellow in the University of Liverpool. Acknowledgements This research was funded in part by the Engineering and Physical Science Research Council of UK under the grant EP/D068606/1, the National Natural and Science Foundation of China under grant no. 60976075, and the Suzhou Science and Technology Bureau of China under grant SYG201007. References 1.