Dielectric and impedance properties of Bi(Zn2/3V1/3)O3 electronic material

A polycrystalline vanadium doped lead free dielectric material of Bi(Zn_2/3V_1/3)O₃ (BZV) has been prepared using a standard high-temperature solid state reaction technique. Its temperature and frequency dependent capacitive, conductive and resistive characteristics are outlined though experimental investigation. The formation of single phase compound of BZV material with orthorhombic crystal symmetry is identified through X-ray diffraction data analysis, and the homogeneous distribution of grains are realized through scanning electron micrograph. The acquaintance of frequency–temperature dependent electrical parameters with the obtained micrograph provides the experimental evidence of contributions of grain as well as grain boundary in its capacitive and resistive characteristics. The negative temperature coefficient of resistance behaviour of the material is revealed from impedance characteristic, and non-Debye type relaxation has been realized from the Nyquist plot. The charge carriers of this electronic compound have both long & short range order that has been validated from the complex modulus and impedance analysis. The prepared electronic material substantiate some important dielectric features which props up the material as promising component for electronic devices.     

Theoretical studies of one- and two-photon absorption properties for three molecules with different centers (B and N) and peripheral substituted groups [N(CH3)2 and CN]

Three molecules with different centers (boron and nitrogen) and peripheral substituted groups [N(CH₃)₂ and CN] have been theoretically studied with B3LYP/6-31G(d) associated with ZINDO and sum-over-states methods. The maximum two-photon absorption cross-section δ_max of the molecule with boron (B) center and N(CH₃)₂ peripheral group is larger than that of the molecule with nitrogen (N) center and N(CH₃)₂ peripheral group. As for the two molecules with N center, the δ_max is obviously increased with the change from N(CH₃)₂ to CN group. This indicates that the large intramolecular charge transfer is in favor of the TPA response.