Study of two tungstates Ca0.5 Cd0.5 WO4 and Ca0.2 Cd0.8 WO4 by transmission electron microscopy

A Taoufyq; L Patout; F Guinneton; A Benlhachemi; B Bakiz; S Villain; A Lyoussi; G Nolibe; J-R Gavarri

doi:10.1111/jmi.12311

Study of two tungstates Ca0.5 Cd0.5 WO4 and Ca0.2 Cd0.8 WO4 by transmission electron microscopy

J Microsc. 2015 Jan;261(1):14-26. doi: 10.1111/jmi.12311. Epub 2015 Sep 15.

Authors

A Taoufyq^{1

2}, L Patout¹, F Guinneton¹, A Benlhachemi², B Bakiz², S Villain¹, A Lyoussi³, G Nolibe⁴, J-R Gavarri¹

Affiliations

¹ Institut Matériaux Microélectronique et Nanosciences de Provence, Aix Marseille Université, CNRS, Université de Toulon, La Garde, France.
² Laboratoire Matériaux et Environnement LME, Faculté des Sciences, Université Ibn Zohr, Cité Dakhla, Agadir, Maroc.
³ CEA, DEN, Département d'Etudes des Réacteurs, Service de Physique Expérimentale, Laboratoire Dosimétrie Capteurs Instrumentation, Saint-Paul-lez-Durance, France.
⁴ Société CESIGMA, Signals & Systems, Chemin de La Planquette, La Garde, France.

PMID: 26372831
DOI: 10.1111/jmi.12311

Abstract

To better understand the role of crystal structures and local disorder in the photonic properties of the system (1 - x)CaWO4 - xCdWO4 with 0 < x < 1, two specific phases with compositions x = 0.5 (scheelite phase) and 0.8 (wolframite phase) have been studied by scanning and transmission electron microscopies. High-resolution electron microscopy images and image simulations, associated with X-ray diffraction data, allowed confirming the lattices and space groups I41 /a and P2/c of the two scheelite and wolframite phases, at the local scale. The electron microscopy data show the existence of a high degree of crystallization associated with statistical distribution of Ca or Cd atoms on a Ca1- x Cdx site in each lattice.

Keywords: Calcium cadmium tungstates; electron microscopy; high-resolution electron microscopy; simulated images; solid solutions.

Publication types

Research Support, Non-U.S. Gov't