Magnetic studies of manganese oxide octahedral molecular sieves: A new class of spin glasses

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00040a016· OSTI ID:7166629

Suib, S L ^[1]; Iton, L E ^[2]

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1. Univ. of Connecticut, Storrs, CT (United States)
2. Argonne National Lab., IL (United States)

Ac and dc magnetic susceptibility measurements of octahedral molecular sieves (OMS) of mixed-valent manganese oxide composition such as (Mg[sup 2+][sub 0.98[minus]1.35]Mn[sup 2+][sub 1.89[minus]1.94]Mn[sup 4+][sub 4.38[minus]4.54])O[sub 12]4.47-4.55H[sub 2]O for synthetic todorokite and KMn[sub 8]O[sub 16] for synthetic cryptomelane are reported here. Data for temperature and frequency dependence of the real components of the ac susceptibility suggest that synthetic cryptomelane (K-OMS-2) materials are spin glasses having a typical T[sub f]([omega]) dependence. The imaginary components of the ac susceptibility at various frequencies also show behavior that is typical of spin glass systems. Zero-field-cooled and field-cooled dc magnetization data as a function of temperature exhibit irreversibility, again consistent with the spin glass assignment for synthetic cryptomelane. Synthetic todorokite having a 3 [times] 3 MnO[sub 6] octahedral tunnel structure does not appear to be a true spin glass. 31 refs., 9 figs.

• OSTI ID: 7166629
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 6:4; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
CHALCOGENIDES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MANGANESE COMPOUNDS
MANGANESE OXIDES
METALLIC GLASSES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS