Structural Characterization of B-Site Ordered Ba2 Ln2/3 TeO6 (Ln = La, Pr, Nd, Sm, and Eu) Double Perovskites and Probing Its Luminescence as Eu3+ Phosphor Hosts

Inorganic Chemistry
Sariga C LalSubodh Ganesanpotti

Abstract

Ba2Ln2/3TeO6 (Ln = La, Pr, Nd, Sm, and Eu) double perovskites were synthesized via solid-state ceramic route. Preliminary X-ray diffraction studies indicated a pseudocubic structure with lattice parameters ranging from 8.55 to 8.44 Å for the substitution of rare earths from La to Eu. Raman spectra show the frequency dependence of various Raman bands with respect to rare-earth substitution and exhibit a significant shift in peaks to higher wavenumber region, which was observed only for symmetric stretching modes of LnO6 and TeO6 octahedra. In accordance with observed number of bands and group theoretical predictions, the most likely symmetry of all compounds in the Ba2Ln2/3TeO6 system was found to be monoclinic with P21 /n space group. Rietveld refinement of the XRD patterns further confirmed the P21 /n space group and also the 1:1 rock salt ordering of the B-site cations. Diffuse reflectance spectra of Ba2Ln2/3TeO6 showed the optical bandgaps of these compounds between 3.9 and 4.8 eV, indicating the suitability as luminescent host material. The reduction in bandgap energy with lanthanide contraction of rare-earth ions is attributed to the widening of conduction band with octahedral tilting. Photoluminescence (PL) spectra and PL...Continue Reading

References

Aug 30, 2003·Acta Crystallographica. Section B, Structural Science·Christopher J HowardPatrick M Woodward
Feb 14, 2006·The Journal of Physical Chemistry. B·Yukari FujiokaMasato Kakihana
May 1, 2010·ACS Applied Materials & Interfaces·Chien-Hao HuangTeng-Ming Chen
Apr 10, 2013·Journal of Physics. Condensed Matter : an Institute of Physics Journal·Mohammad A IslamJonathan E Spanier
Dec 19, 2013·Chemical Society Reviews·Mengmeng ShangJun Lin
Feb 13, 2015·Dalton Transactions : an International Journal of Inorganic Chemistry·R L AndrewsP M Woodward
May 12, 2016·Physical Chemistry Chemical Physics : PCCP·Qingfeng GuoLefu Mei

❮ Previous
Next ❯

Related Concepts

Related Feeds

Cardiac Conduction System

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.