@article{189ae84c9a5c4e97b44e149ecf3419c3,
title = "Evolution of surface and sub-surface morphology and chemical state of exsolved Ni nanoparticles",
abstract = "Nanoparticle formation by dopant exsolution (migration) from bulk host lattices is a promising approach to generate highly stable nanoparticles with tunable size, shape, and distribution. We investigated Ni dopant migration from strontium titanate (STO) lattices, forming metallic Ni nanoparticles at STO surfaces. Ex situ scanning probe measurements confirmed the presence of nanoparticles at the H2 treated surface. In situ ambient pressure X-ray photoelectron spectroscopy (AP-XPS) revealed reduction from Ni2+ to Ni0 as Ni dopants migrated to the surface during heating treatments in H2. During Ni migration and reduction, the Sr and Ti chemical states were mostly unchanged, indicating the selective reduction of Ni during treatment. At the same time, we used in situ ambient pressure grazing incidence X-ray scattering (GIXS) to monitor the particle morphology. As Ni migrated to the surface, it nucleated and grew into compressed spheroidal nanoparticles partially embedded in the STO perovskite surface. These findings provide a detailed picture of the evolution of the nanoparticle surface and subsurface chemical state and morphology as the nanoparticles grow beyond the initial nucleation and growth stages.",
author = "Heath Kersell and Weber, {Moritz L.} and Lorenz Falling and Qiyang Lu and Christoph Baeumer and Nozomi Shirato and Volker Rose and Christian Lenser and Felix Gunkel and Slavomir Nemsak",
note = "Funding Information: This work was associated with the development of instrumentation through the Laboratory Directed Research and Development (LDRD) Program at Lawrence Berkeley National Laboratory under a grant titled “Correlation of structural and chemical processes at interfaces under operating conditions using multimodal ambient pressure X-ray photoelectron spectroscopy and surface X-ray scattering.” S. N. and H. K. acknowledge this LDRD grant for salary support. Part of this work was performed at beamline 11.0.2 of the Advanced Light Source, a U.S. DOE Office of Science User Facility, which is funded under Contract No. DE-AC02-05CH11231. LJF acknowledges support from the Alexander von Humboldt Foundation, Bonn, Germany. Part of this work was performed at the Advanced Photon Source and the Center for Nanoscale Materials, U. S. Department of Energy Office of Science User Facilities, and supported by the U. S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The authors thank D. Rosenmann and Y. Liu for their help with smart tip fabrication at XTIP. Publisher Copyright: {\textcopyright} 2022 The Royal Society of Chemistry.",
year = "2022",
month = aug,
day = "1",
doi = "10.1039/d1fd00123j",
language = "English",
volume = "236",
pages = "141--156",
journal = "Faraday discussions",
issn = "1359-6640",
publisher = "Royal Society of Chemistry",
}