Processing of sodium-potassium niobate ceramics

Thesis/Dissertation · Thu Dec 02 04:00:00 EST 1971

DOI:https://doi.org/10.2172/4701954· OSTI ID:4701954

Powell, Jr, Bob R. ^[1]

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1. Univ. of California, Berkeley, CA (United States)

Sintering studies of undoped (Na_0.5K_0.5)NbO₃ and the same material doped with 1/2, 1, 2, and 4 mole percent BaO and 2 mole % B₂O₃ were made. The persistence of a second phase after calcining to form the compound led to a study of reactions occurring during calcination. The calcining of sodium-potassium niobates involves the formation of an intermediate compound (the second phase) and its subsequent reaction with sodium oxide and potassium oxide to form (Na_0.5K_0.5)NbO₃. Sintering data show that up to 1/2 mole % BaO added to the system increases the initial densification. However, the sintered bodies then exhibit densification and form sharp cubic grains and large voids. Indications are that a liquid phase is the major contributor to densification of this system through the mechanism of particle rearrangement, and that the contribution of any sintering mechanism to densification is negligible.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-26-022493
• OSTI ID: 4701954
• Report Number(s): LBL--413
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
BORON OXIDES
DOPED MATERIALS
NIOBIUM OXIDES
PHASE STABILITY
POTASSIUM COMPOUNDS
POTASSIUM SODIUM NIOBATES/phase studies of undoped and barium oxide and boron oxide doped
SODIUM COMPOUNDS