TY - JOUR
T1 - Effect of non-stoichiometry on the densification, phase purity, microstructure, crystal structure, and dielectric loss of Ba(Co1/3Nb2/3)O3 ceramics
AU - Sayyadi-Shahraki, Ahmad
AU - Taheri-Nassaj, Ehsan
AU - Gonzales, Justin
AU - Newman, Nathan
AU - Kolodiazhnyi, Taras
N1 - Funding Information:
The use of facilities in the LeRoy Eyring Center for Solid State Science (LECSSS) at Arizona State University is acknowledged. A.S. thanks Prof. Vaclav Petricek for his useful advice on Rietveld refinement with Jana 2006 software. Collaboration between Dr. T. Kolodiazhnyi (NIMS) and Prof. N. Newman (ASU) was partially supported by Grant-in-Aid for Scientific Research 26400323 from JSPS.
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/8
Y1 - 2017/8
N2 - The structural, vibrational, densification, and microwave properties of Ba(Co1/3Nb2/3)O3 ceramics with small compositional variations along several tie lines in the ternary BaO–CoO–Nb2O5 diagram were studied. The results showed that very small deviation from stoichiometric Ba(Co1/3Nb2/3)O3 composition has profound effect on Q × f, degree of ordering, densification, and phase assemblage. The 0.94 Ba(Co1/3Nb2/3)O3–0.06 Ba5Nb4O15 ceramic has the highest Q × f value (71 THz) – a value two times larger than that of stoichiometric Ba(Co1/3Nb2/3)O3 (36 THz). Transformation from the (partial) disordered distribution of Co and Nb cations to 1:2 ordered arrangement in the octahedral sites was found to increase the Q factor of the high density and single phase ceramics. It was also observed that formation of very small amount of Ba9CoNb14O45 second phase degraded Q × f value severely for the dense and highly ordered Nb-rich and Ba-deficient ceramics.
AB - The structural, vibrational, densification, and microwave properties of Ba(Co1/3Nb2/3)O3 ceramics with small compositional variations along several tie lines in the ternary BaO–CoO–Nb2O5 diagram were studied. The results showed that very small deviation from stoichiometric Ba(Co1/3Nb2/3)O3 composition has profound effect on Q × f, degree of ordering, densification, and phase assemblage. The 0.94 Ba(Co1/3Nb2/3)O3–0.06 Ba5Nb4O15 ceramic has the highest Q × f value (71 THz) – a value two times larger than that of stoichiometric Ba(Co1/3Nb2/3)O3 (36 THz). Transformation from the (partial) disordered distribution of Co and Nb cations to 1:2 ordered arrangement in the octahedral sites was found to increase the Q factor of the high density and single phase ceramics. It was also observed that formation of very small amount of Ba9CoNb14O45 second phase degraded Q × f value severely for the dense and highly ordered Nb-rich and Ba-deficient ceramics.
KW - Cation ordering
KW - Dielectric loss
KW - Microstructure
KW - Point defects
KW - Sintering
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U2 - 10.1016/j.jeurceramsoc.2017.04.023
DO - 10.1016/j.jeurceramsoc.2017.04.023
M3 - Article
AN - SCOPUS:85017444602
SN - 0955-2219
VL - 37
SP - 3335
EP - 3346
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 10
ER -