Near Atomic Scale Studies of Electronic Structure at Grain Boundaries in N<span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">i</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>Al

David A. Muller; Shanthi Subramanian; Philip E. Batson; Stephen L. Sass; John Silcox

doi:10.1103/PhysRevLett.75.4744

Near Atomic Scale Studies of Electronic Structure at Grain Boundaries in N $i_{3}$ Al

David A. Muller, Shanthi Subramanian, Philip E. Batson, Stephen L. Sass, and John Silcox

Phys. Rev. Lett. 75, 4744 – Published 25 December 1995

Abstract

Why does boron doping improve the room temperature ductility of polycrystalline ${Ni}_{3} Al$ ? Besides preventing environmental embrittlement, B changes the fracture mode from intergranular to transgranular, suggesting an increase in the cohesive strength of the grain boundaries. This change in bonding at the grain boundary has been measured using spatially resolved electron energy loss spectroscopy. The Ni $L_{2, 3}$ core edge, which is sensitive to the filling of the Ni $d$ band, shows that only the B-rich regions of the grain boundary have a bonding similar to that of the bulk material. These changes suggest a simple model to describe the cohesion of the boundary.

Received 19 June 1995

DOI:https://doi.org/10.1103/PhysRevLett.75.4744

Authors & Affiliations

David A. Muller¹, Shanthi Subramanian², Philip E. Batson³, Stephen L. Sass², and John Silcox¹

¹School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853
²Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853
³IBM Thomas J. Watson Research Center, Yorktown Heights, New York