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The Influence of Cation Additives on Grain‐Boundary Mobility in Yttrium Aluminum Garnet (YAG)
Author(s) -
Zamir Shlomit
Publication year - 2015
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13290
Subject(s) - materials science , dopant , yttrium , grain boundary , grain growth , doping , sintering , intergranular corrosion , phase (matter) , mineralogy , analytical chemistry (journal) , metallurgy , grain size , microstructure , chemistry , oxide , optoelectronics , chromatography , organic chemistry
Pure yttrium aluminum garnet ( YAG ) nano‐powders, doped with 1.4 at.% of La 2 O 3 , ZrO 2 , MgO , Nb 2 O 5 , and SiO 2, were vacuum sintered to full density and subjected to grain growth at 1700°C, for up to 15 h. The YAG intrinsic grain‐boundary ( GB ) mobility, determined from the pure fully dense YAG specimens, was 2.9 × 10 −16 [m 3 ·N −1 ·s −1 ]. All dopants, except for La 2 O 3 , increased the GB mobility compared to pure YAG ( La 2 O 3 didn't cause any significant change in YAG 's GB mobility). All GB s were found to be free of secondary phases or intergranular films. These findings differ from numerous publications where dopants were found to either inhibit grain growth by solute drag, or to enhance grain growth due to liquid phase sintering. It was found that the GB mobility systematically increased with the decrease in the dopant cation radius. Moreover, it seems that vacancy population plays an important role in determining the GB mobility of YAG .