Structural study and electrical properties of Zr-doped Nd2Sn2O7 pyrochlore compounds

Pramana

Keka Chakraborty²  A Das²  P B Joshi¹  Y D Kolekar1³  S B Kulkarni¹  S K Paranjpe3² 

[1] Physics Department, Shivaji University PG Centre, Solapur 413 255, India$$;Condensed Matter Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India$$;Physics Department, Shivaji University, Kolhapur 416 004, India$$

关键词: Pyrochlores;    neutron diffraction;    complex impedance spectroscopy.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Nd2Sn2O7 pyrochlores with the substitution of Zr4+ were prepared by conventional ceramic double sintering technique. The single-phase formation was confirmed by X-ray diffraction and neutron diffraction techniques. Relative intensity calculations for X-ray diffraction analysis were performed for oxygen positional parameters 𝑥 = 0.331 and 0.375, while Rietveld refinements were employed for neutron diffraction data. The neutron diffraction study revealed that there are only two anion sites with 48f and 8b positions. This indicates that the 8a site, i.e. O(3) sublattice, is completely vacant and the structure is a perfect cubic pyrochlore with space group Fd3m (O$_{h}^{7}$).From the conductivity measurements, it is observed that the electronic conductivity dominates from room temperature up to about 525 K and for T > 525 K, the oxygen ion conduction dominates the charge transport in these compositions. Complex impedance spectroscopy indicates the existence of grain and grain boundary as two separate elements.

【 授权许可】

Unknown