Chemical hysteresis in phase transitions in the TbO--O system

Journal Article · Fri Aug 01 04:00:00 EDT 1975 · J. Solid State Chem., v. 14, no. 4, pp. 383-394

DOI:https://doi.org/10.1016/0022-4596(75)90060-2· OSTI ID:4163244

Lowe, A T; Eyring, L

A thermogravimetric study of hysteresis in the TbO/sub x/--O$sub 2$ system has provided insight into phase transitions occurring among the fluorite- related rare earth oxides. A series of isobaric scanning loops at 380 torr have been made. The scans were between TbO$sub 1$$.$$sub 5$(phi) and TbO$sub 1$$.$$sub 714$(l) at higher temperatures and between TbO$sub 1$$.$$sub 714$(l) and TbO$sub 1$$.$$sub 81$$sub 8$(delta) at lower temperatures. Corresponding isobaric studies were made utilizing high temperature x-ray powder diffraction to augment the TGA experiments. It was confirmed that sections of the lower temperature loop were dependent on the rate of temperature change while the higher temperature loop was entirely reproducible. Interior scanning loops made within the lower hysteresis loop showed univariant behavior typical of a single phase when reversed in the delta'delta pseudophase region, otherwise it exhibited bivariant behavior. The upper hysteresis loop showed bivariant behavior throughout the interior of the loop. Some thermodynamic aspects and the microdomain concept as applied to hysteresis are also considered. (auth)

• Research Organization: Arizona State Univ., Tempe
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-003424
• OSTI ID: 4163244
• Journal Information: J. Solid State Chem., v. 14, no. 4, pp. 383-394, Journal Name: J. Solid State Chem., v. 14, no. 4, pp. 383-394; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

*TERBIUM OXIDES-- PHASE TRANSFORMATIONS
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Cermets & Refractories-- Structure & Phase Studies
HYSTERESIS
LOW PRESSURE
N50130* --Metals
Ceramics
& Other Materials--Ceramics & Cermets--Properties
Structure & Phase Studies
OXYGEN
TEMPERATURE DEPENDENCE
THERMAL GRAVIMETRIC ANALYSIS