Production of Ni(OH)2-monolayer-microclusters

doi:10.1016/0921-4526(94)90478-2

Physica B: Condensed Matter

Volumes 194–196, Part 1, 2 February 1994, Pages 297-298

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Abstract

By the chemical, magnetic and X-ray-analysis, the production of Ni(OH)₂-monolayer-microclusters was identified in the precipitates from the mixing of aqueous solutions of NiCl₂·6H₂O and Na₂SiO₃·nH₂O (n=0 or 9). The magnetic transition temperature of 10.2K was discussed, based on the finite size effect in the magnetic microcluster.

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Cited by (6)

X-ray absorption fine-structure study on the Ni(OH)<inf>2</inf> monolayer nanoclusters
2003, Chemical Physics Letters
Citation Excerpt :
Encapsulation in a silica cage is one of the ways to prepare nanoclusters. Recently, one of the present authors has produced Ni(OH)2-monolayer nanoclusters [1–3] encapsulated in a silica cage. This nanocluster exhibits ferromagnetism below 10 K, as confirmed by dc and ac magnetic susceptibility measurements [4].
The local structure around Ni ion for Ni(OH)₂ monolayer nanocluster (Ni-MNC) was studied by Ni K-edge X-ray absorption fine-structure spectroscopy (XAFS). XAFS analyses were consistent with the monolayer formation of the nanoclusters. We found that the Ni–Ni distance in the monolayer plane exhibits a significant contraction compared to that in bulk Ni(OH)₂, while the spacing between the Ni and O layers are rather expanded. Such a structural change is discussed in relation to the magnetic property of the Ni-MNC, which exhibits ferromagnetism below 10 K with a higher exchange interaction between the in-plane Ni atoms than that of the bulk Ni(OH)₂.
Magnetic susceptibility of Ni(OH)<inf>2</inf> monolayer nanoclusters
1998, Journal of Magnetism and Magnetic Materials
DC magnetic susceptibilities χ were measured for Ni(OH)₂ monolayer nanoclusters (Ni-MNC) which were randomly comprised by amorphous SiO₂. The χ showed the Curie–Weiss behavior between about 100 and 300 K, and it deviated from the Curie–Weiss law below about 100 K. The χ-data were compared with the high temperature series expansion (HTSE) theory for 2D Ising ferromagnet, and it was found that the short range order effect in the 2D Ising system was dominant for the magnetism of Ni-MNC between 16 and 100 K. The analysis by the superparamagnetic model showed a gradual increase of the ferromagnetic Ni²⁺ cluster size in each Ni-MNC. The quantum size effect in Ni-MNC was also discussed by the modified HTSE theory.
Frequency dependent magnetic susceptibility of Ni(OH)<inf>2</inf> monolayer nanoclusters
1996, Materials Science and Engineering: A
The a.c. magnetic susceptibility χ_ac was measured for Ni(OH)₂ monolayer nanoclusters (Ni-MNC) in the temperature region 4.2–20 K. The frequency dependence of χ_ac was investigated between 98 Hz and 8 kHz with an a.c. field amplitude of 1.8 Oe. The magnetic freezing temperature T′_f was measured above 10 K using the real and imaginary parts of χ_ac, (χ′₀, χ′'₀). The value of dynamic critical exponent zv was determined by applying a dynamic scaling law to the present results. It is considered that the finite two-dimensional ferromagnetic system of Ni-MNCs has magnetic order at 9.5 K, at which the non-linear a.c. magnetic susceptibility χ′₂ has an anomalous dip.
AC magnetic susceptibility of Ni(OH)<inf>2</inf> monolayered microclusters
1995, Journal of Magnetism and Magnetic Materials
Syntheses and properties of cobalt and nickel hydroxide nanosheets
2010, International Journal of Modern Physics B
Preparation of magnetic nanoparticles using chemical route and functionalization for medical applications
2010, Nanomagnetism and Spintronics: Fabrication, Materials, Characterization and Applications

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Production of Ni(OH)2-monolayer-microclusters

Abstract

J.M.M.M.

J.M.M.M.

J. Chem. Thermodynamics

Production of Ni(OH)₂-monolayer-microclusters