Phase Evolution and Microstructural Studies in CaZrTi2O7–Nd2Ti2O7 System. Issue 2 (7th December 2013)

• Record Type: Journal Article
• Authors: Jafar, Mohsin; Sengupta, Pranesh; Achary, Srungarpu N.; Tyagi, Avesh K.; Vance, L.
• Is Part Of: Journal of the American Ceramic Society. Volume 97:Issue 2(2014)
• Page Start: 609
• Page End: 616
• Publication Date: 2013-12-07
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12664
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12664-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>A series of compositions with general stoichiometry Ca<sub>1−<italic>x</italic></sub>Zr<sub>1−<italic>x</italic></sub>Nd<sub>2<italic>x</italic></sub>Ti<sub>2</sub>O<sub>7</sub> has been prepared by high‐temperature solid‐state reaction of component oxides and characterized by powder X‐ray diffraction and electron probe for microanalyses (EPMA). The phase fields in CaZrTi<sub>2</sub>O<sub>7</sub>–Nd<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> system and distribution of ions in different phases have been determined. Four different phase fields, namely monoclinic zirconolite, cubic perovskite, cubic pyrochlore, and monoclinic Nd<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> structure types are observed in this system. The 4M‐polytype of zirconolite structure is stabilized by substitution of Nd<sup>3+</sup> ion. The addition of Nd<sup>3+</sup> ions form a cubic perovskite structure‐type phase and thus observed in all the compositions with 0.05 ≤ <italic>x</italic> ≤ 0.80. Cubic pyrochlore structure‐type phase is observed as a coexisting phase in the nominal composition with 0.20 ≤ <italic>x</italic> ≤ 0.90. Only a subtle amounts of Ca<sup>2+</sup> and Zr<sup>4+</sup> are incorporated into the perovskite‐type Nd<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> structure. EPMA analyses on different coexisting phases revealed that the pyrochlore and perovskite phases have Nd<sup>3+</sup>‐rich compositions.</p> </abstract>