title: Grain boundary strengthening in alumina by rare earth impurities.
abstract: Impurity doping often alters or improves the properties of materials. In alumina, grain boundaries play a key role in deformation mechanisms, particularly in the phenomenon of grain boundary sliding during creep at high temperatures. We elucidated the atomic-scale structure in alumina grain boundaries and its relationship to the suppression of creep upon doping with yttrium by using atomic resolution microscopy and high-precision calculations. We find that the yttrium segregates to very localized regions along the grain boundary and alters the local bonding environment, thereby strengthening the boundary against mechanical creep.
authors.affiliation: Institute of Engineering Innovation, University of Tokyo, 2-11-16, Yayoi, Bunkyo, Tokyo 113-8656, Japan.
authors.forename: J P
authors.initials: JP
authors.lastname: Buban
authors.forename: K
authors.initials: K
authors.lastname: Matsunaga
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Shibata
authors.forename: W Y
authors.initials: WY
authors.lastname: Ching
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Ikuhara