Effect of Samarium Modification on Structural and Dielectric Properties of (PbSm)(ZrSnTi)O3 System
Samples with representative formula Pb(1–1.5x)Smx(Zr0.7Sn0.3)0.938Ti0.062O3 (PSmZST) with x = 0.0, 0.01, 0.02 and 0.04 were synthesized using conventional solid state ceramic route. Dielectric properties were studied as a function of frequency and temperature. Dielectric constant curves show a hump before the paraelectric transition. Dielectric loss measurements show noticeable changes as compare to the unmodified composition. ac conductivity measurements show that conductivity of samples increases with increase of samarium (Sm) content.
A 13C nmr study of a diazo, of two diazonium salts and of some other model pyrazole compounds is reported. It is found that the C-4 diazo carbon is more shielded than the normal sp2 pyrazole hybridized carbon, while its diazonium salt is more deshielded. The electron density on the C-4 of the diazopyrazole is probably due to the positive charge on the terminal nitrogen. Thus the 13C chemical shift values allowed us to understand the chemical behaviour of a compound of potential antitumor activity.