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Time domain measurement is an indispensable experimental method for ultralow frequency region (even lower than 1 Hz) and nonlinearity study of ferroelectric materials. The charging and discharging currents of BaTi1-xSnxO3 (BTS) ceramics have been collected in both paraelectric and ferroelectric phases. Kohlrausch-Williams- Watts (KWW) relation with two parameters (β and τ) was employed in discharging current analysis. Our results show that the higher β values in paraelectric phase indicate near Debye relaxation behavior, and lower βvalues in ferroelectric phase tie with possible diffusion controlled universal relaxation law (URL). [ABSTRACT FROM AUTHOR]

Tin-based nanoparticles, proposed to be barium stannate, have been formed in YBCO films fabricated by metal-organic deposition, through modification of the precursor solution. These randomly-oriented 30-50 nm particles are dispersed throughout the film thickness, providing an enhancement in the isotropic flux pinning relative to undoped YBCO. For a low level, of nanopartide addition of 2 vol%, a flux-pinning force enhancement of up to 32% is achieved. We report field and field-angle dependence of the transport critical current, transmission electron microscopy, and x-ray diffraction of our YBCO films on RABiTS substrates, and compare with similar barium zirconate additions. [ABSTRACT FROM AUTHOR]