Positronic probe of vacancy defects on surfaces of Au nanoparticles embedded in MgO

Journal Article · Sat Sep 15 04:00:00 EDT 2001 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.64.113404· OSTI ID:40277576

Xu, Jun; Moxom, J; Somieski, B; White, C W; Mills, A P; Suzuki, R; Ishibashi, S

Clusters of four atomic vacancies were found in Au nanoparticle-embedded MgO by positron lifetime spectroscopy [Phys. Rev. Lett. 83, 4586 (1999)]. These clusters were also suggested to locate at the surface of Au nanoparticles by one-detector measurements of Doppler broadening of annihilation radiation. In this work we provide evidence, using two-detector coincidence experiments of Doppler broadening (2D-DBAR), to clarify that these vacancy clusters reside on the surfaces of Au nanoparticles. This work also demonstrates a method for identifying defects at nanomaterials interfaces: a combination of both positron lifetime spectroscopy, which tells the type of the defects, and 2D-DBAR measurements, which reveals chemical environment of the defects.

• Research Organization: Oak Ridge National Laboratory
• Sponsoring Organization: (US)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 40277576
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 11 Vol. 64; ISSN 0163-1829
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANNIHILATION
DEFECTS
DOPPLER BROADENING
LIFETIME
POSITRONS
PROBES
SPECTROSCOPY
VACANCIES