Chen Y, Yang J, Jiang P, Jiang F, Wei H, Gao W, Cong R, Yang T. Structural Diversity and Incompatibility Induced Complex Phase Formation Behavior in the Stuffed Tridymites Ca
1-xSr
xGa
2O
4.
Inorg Chem 2021;
60:12580-12590. [PMID:
34350764 DOI:
10.1021/acs.inorgchem.1c01897]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Stuffed tridymites AM2O4 composed of a condensed MO4-tetrahedra-based framework have been widely investigated due to their structural diversity and rich physical properties. Herein, the strategy of stuffing mixed Ca2+ and Sr2+ cations into the [Ga2O4]2- framework in (Ca1-xSrx)Ga2O4 (CSGO, 0 ≤ x ≤ 1) is utilized to manipulate the phase formation behavior with different structure types at particular annealing temperatures. Five derivatives, including α- and β-CaGa2O4, β- and γ-SrGa2O4, and new CSGO-type structures, were observed. The distinctive feature of the CSGO-structure is the coexistence of UUDDUD- and UDUDUD-type six-membered rings, where U (up) and D (down) denote the orientations of GaO4-tetrahedra with respect to the plane grids, in a ratio of 2:1. Single-phase α-Ca1-xSrxGa2O4 (x < 0.2) and γ-Ca1-xSrxGa2O4 (x > 0.67) could be obtained at low temperatures. Biphasic regions, including α-Ca1-xSrxGa2O4/CSGO (0.2 ≤ x ≤ 0.67), γ-Ca1-xSrxGa2O4/CSGO (0.67 < x ≤ 0.8), and β-Ca1-xSrxGa2O4/CSGO (0.8 < x < 1), were observed at the intermediate temperature region and evolve irreversibly into the CSGO single-phase region upon elevating the temperature. Moreover, the structure-property relationship of the new CSGO-phase was further studied by doping coordination-sensitive Bi3+ activators to advance the development and applications of stuffed tridymites.
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