The structure and ordering of {epsilon}-MnO{sub 2}
- Department of Materials Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7204 (United States)
- Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810 (United States)
- Energizer Battery Manufacturing, 25225 Detroit Rd., Westlake, OH 44145 (United States)
The presence of {epsilon}-MnO{sub 2} as a major component of electrolytic manganese dioxide (EMD) has been demonstrated by a combined X-ray diffraction/transmission electron microscopy (TEM) study. {epsilon}-MnO{sub 2} usually has a partially ordered defect NiAs structure containing 50% cation vacancies; these vacancies can be fully ordered by a low temperature (200 deg. C) heat treatment to form a pseudohexagonal but monoclinic superlattice. Numerous fine-scale anti-phase domain boundaries are present in ordered {epsilon}-MnO{sub 2} and cause extensive peak broadening and a massive shift of a very intense, 0.37 nm superlattice peak. This suggests a radically different explanation of the ubiquitous, very broad {approx}0.42 nm peak ({approx}21-22 deg. 2{theta}, CuK{alpha} radiation) in EMDs, which heretofore has been attributed to Ramsdellite containing numerous planar defects. This work confirms the multi-phase model of equiaxed EMDs proposed by Heuer et al. [ITE Lett. 1(6) (2000) B50; Proc. Seventh Int. Symp. Adv. Phys. Fields 92 (2001)], rather than the defective single-phase model of Chabre and Pannetier [Prog. Solid State Chem. 23 (1995) 1] and Bowden et al. [ITE Lett. 4(1) (2003) B1].
- OSTI ID:
- 20784919
- Journal Information:
- Journal of Solid State Chemistry, Vol. 179, Issue 3; Other Information: DOI: 10.1016/j.jssc.2005.11.042; PII: S0022-4596(05)00573-6; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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