TY - JOUR
T1 - Characterization of metal precipitates in magnesium oxide
AU - Narayan, J.
AU - Chen, Y.
AU - Moon, R. M.
AU - Carpenter, Ray
N1 - Funding Information:
ACKNOWLEDGMENT This research was sponsored by the Division of Materials Sciences, U.S. Department of Energy, under contract W-7405-eng-26 with Union Carbide Corporation.
PY - 1984/8
Y1 - 1984/8
N2 - A method, based on subtractive coloration or high-temperature reduction, has been developed to produce metal precipitates or colloids in oxides. The structure, symmetry, morphology and composition of precipitates were analysed by analytical electron microscopy and neutron scattering techniques. In the MgO: Ni system, the colloids were coherent nickel precipitates having a f.c.c. structure (ao = 3·52 Å), and occasionally a b.c.c. structure (ao = 2·88Å). The coherent precipitates were found to have either ⟨100⟩m‖⟨111⟩p or ⟨100⟩m‖⟨100⟩p matrix-precipitate relationship, depending on the high-temperature reduction treatment. From the neutron-magnetic-scattering measurements, the ratio of magnetic to nuclear scattering amplitudes for the (111) precipitate reflection was determined to be 17% below the value for pure nickel, indicating the presence of a magnetically ‘dead’ layer around the precipitates, a small amount of impurities incorporated into the precipitates, or a small fraction of another phase of nickel.
AB - A method, based on subtractive coloration or high-temperature reduction, has been developed to produce metal precipitates or colloids in oxides. The structure, symmetry, morphology and composition of precipitates were analysed by analytical electron microscopy and neutron scattering techniques. In the MgO: Ni system, the colloids were coherent nickel precipitates having a f.c.c. structure (ao = 3·52 Å), and occasionally a b.c.c. structure (ao = 2·88Å). The coherent precipitates were found to have either ⟨100⟩m‖⟨111⟩p or ⟨100⟩m‖⟨100⟩p matrix-precipitate relationship, depending on the high-temperature reduction treatment. From the neutron-magnetic-scattering measurements, the ratio of magnetic to nuclear scattering amplitudes for the (111) precipitate reflection was determined to be 17% below the value for pure nickel, indicating the presence of a magnetically ‘dead’ layer around the precipitates, a small amount of impurities incorporated into the precipitates, or a small fraction of another phase of nickel.
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U2 - 10.1080/01418618408234929
DO - 10.1080/01418618408234929
M3 - Article
AN - SCOPUS:0021373277
VL - 49
SP - 287
EP - 300
JO - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
JF - Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties
SN - 0141-8610
IS - 2
ER -