title: Atomic-resolution imaging of the nanoscale origin of toughness in rare-earth doped SiC.
abstract: Ultrahigh-resolution transmission electron microscopy and atomic-scale spectroscopy are used to investigate the origin of the toughness in rare-earth doped silicon carbide (RE-SiC) by examining the mechanistic nature of the intergranular cracking events which we find to occur precisely along the RE-decorated interface between the SiC grains and the nanoscale grain-boundary phase. We conclude that, for optimal toughness, the relative elastic modulus across the grain-boundary phase and the interfacial fracture toughness are the most critical material parameters; both can be altered with judicious choice of rare-earth elements.
authors.affiliation: Materials Sciences Division, and National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Kueck
authors.forename: Do Kyung
authors.initials: DK
authors.lastname: Kim
authors.forename: Quentin M
authors.initials: QM
authors.lastname: Ramasse
authors.forename: L C
authors.initials: LC
authors.lastname: De Jonghe
authors.forename: R O
authors.initials: RO
authors.lastname: Ritchie