Dipolar chains formed by chemically synthesized cobalt nanocubes

Cheng, Guangjun; Shull, Robert D.; Walker, Angela R. Hight

doi:10.1016/j.jmmm.2009.02.037

Cited by 12 publications

(9 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The respective XRD patterns are collected in Figure 2. The magnetic properties of the Co nanoparticles correspond to those already described in the literature [11,15,20] and will not be discussed. [31] The influence of the following additives has been investigated: (1) cetyltrimethylammonium bromide (CTAB), (2) benzylpyridine (BPy), and (3) mixtures of oleic acid (OS) and oleylamine (OA).…”

Section: Resultsmentioning

confidence: 93%

“…[18][19][20][21][22] Very recent studies have shown that changing the shape of cobalt nanoparticles from spherical to cubic can fundamentally change their magnetic behavior. [15,[23][24][25] Here we describe our observation that the between an additive and the precursor or between two additives. The additional presence of an inhomogeneous magnetic field leads to disc-shaped crystalline nanoparticles, which assemble to chains.…”

Section: Introductionmentioning

confidence: 93%

“…For shape control, it is not important whether the ionic additive is present already from the beginning or formed only during the thermal decomposition. The influence of an external magnetic field during the synthesis of cobalt nanoparticles [26][27][28][29] and the self-organization of cobalt nanoparticles under the influence of an external magnetic field [15,14] are documented in the literature. One-dimensional assemblies have been observed in all cases, and the resulting physical effects have been studied.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Ionic Additives and Weak Magnetic Fields in the Thermal Decomposition of Octacarbonyldicobalt – Tools To Control the Morphology of Cobalt Nanoparticles

et al. 2011

View full text Add to dashboard Cite

In the presence of ionic compounds, the thermal decomposition of octacarbonyldicobalt, Co2(CO)8, in an inert solvent leads exclusively to ϵ‐Co nanocubes. The ionic species can be added directly or generated in situ by a chemical reaction between an additive and the precursor or between two additives. The additional presence of an inhomogeneous magnetic field leads to disc‐shaped crystalline nanoparticles, which assemble to chains.

show abstract

Section: Resultsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ionic Additives and Weak Magnetic Fields in the Thermal Decomposition of Octacarbonyldicobalt – Tools To Control the Morphology of Cobalt Nanoparticles

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Com a aplicação do campo magnético externo, partículas com diâmetro médio de 8 nm e estruturas fcc foram obtidas [43]. A decomposição térmica de precursores de cobalto foi, inclusive, utilizada por outros autores, como por exemplo, em [44][45][46][47][48][49][50].…”

Section: Nanopartículas De Cobalto: Sínteses E Caracterizaçõesunclassified

Nanopartículas magnéticas: o cobalto

Sargentelli

Ferreira

2010

Eclet. Quím.

View full text Add to dashboard Cite

Resumo: O desenvolvimento de nanopartículas magnéticas tem sido levado a cabo devido à sua importância tecnológica. Os materiais nanoparticulados magnéticos exibem uma série de propriedades interessantes, entre as quais citam-se as propriedades elétricas, ópticas, magnéticas e químicas. As nanoestruturas podem ser utilizadas em microeletrônica e em medicina, como em: memória magnética, transporte magnético de complexos bioquímicos, imagem de ressonância magnética, entre outras. As propriedades magnéticas de nanopartículas são muito sensitivas aos seus tamanhos e às suas formas. Nesse sentido, muitos esforços têm sido realizados com o intuito de controlar a forma e a distribuição do tamanho das nanopartículas. Nas últimas décadas nanoestruturas constituídas por óxidos de ferro foram intensamente estudadas. Todavia, mais recentemente, o foco das pesquisas tem se voltado para outros metais de transição. Dentre estes, o cobalto vem sendo investigado em decorrência de sua alta susceptibilidade magnética. Neste contexto, o presente artigo tem o objetivo de apresentar e efetuar uma análise comparativa das mais significativas vias sintéticas empregadas até o presente momento para se obter nanopartículas de cobalto.Palavras-chave: Nanopartículas, cobalto. IntroduçãoAs aplicações de nanopartículas magnéticas vêm permitindo avanços significativos na informação atual sobre esses materiais e nas tecnologias biológi-cas, as quais incluem o armazenamento de informações, sensores magnéticos, bio-separadores e desenvolvimento de novos medicamentos [1-2]. As nanopartículas magnéticas oferecem várias possibilidades de aplicação em biomedicina. Isto porque esses materiais apresentam tamanho na extensão de alguns a dezenas de nanômetros, os quais são menores ou comparáveis ao tamanho de uma célula (10 -100 µm), de um vírus (20 -450 nm), de uma proteína (5 -50 nm) ou de um gene (2 nm de largura e 10 -100 nm de comprimento) [3][4]. Isto significa que as nanopartículas podem ser empregadas como uma entidade biológica.Certamente, esses materiais podem ser revestidos com moléculas biológicas para fazer com que os mesmos interajam com outras espécies biológicas e, desse modo, fornecendo um meio controlável de endereça-mento dessas espécies no organismo [5]. Além disso, os materiais nanoestruturados são magnéticos, o que significa que os mesmos seguem as leis de Coulomb e podem, portanto, serem manipulados por um campo magnético externo [6][7]. Também, as nanopartículas magnéticas podem responder a uma variação magnéti-ca em função do tempo, o que conduz a um efeito de transferência de energia do campo magnético excitante para as nanopartículas [8]. Assim, as nanoestruturas podem sofrer aquecimento, o que propicia o seu uso como agentes epitérmicos ou como agentes quimioterápicos e radioterápicos, conduzindo a uma destruição das células malignas [9].

show abstract

“…Various synthesis strategies have been used in the literature to obtain cobalt nanostructures of desired size and shape such as spherical nanoparticles [ 14 – 15 ] synthesized by high-temperature chemical reduction while controlling the pH value, cobalt–polymer composite tubes [ 16 ] formed by using alumina templates, cobalt cubes [ 17 ] produced in imidazolium ionic liquid or by thermal decomposition [ 18 ]. An alternative way to obtain complex hierarchical nanostructures is the controlled assembly of primary building blocks using electric and magnetic forces, capillary effects, and surface defects.…”

Section: Introductionmentioning

confidence: 99%

Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media

Deshmukh¹,

Mehra²,

Thaokar³

2017

Beilstein J. Nanotechnol.

View full text Add to dashboard Cite

Aggregation and self-assembly are influenced by molecular interactions. With precise control of molecular interactions, in this study, a wide range of nanostructures ranging from zero-dimensional nanospheres to hierarchical nanoplates and spindles have been successfully synthesized at ambient temperature in aqueous solution. The nanostructures reported here are formed by aggregation of spherical seed particles (monomers) in presence of quaternary ammonium salts. Hydroxide ions and a magnetic moment of the monomers are essential to induce shape anisotropy in the nanostructures. The cobalt nanoplates are studied in detail, and a growth mechanism based on collision, aggregation, and crystal consolidation is proposed based on a electron microscopy studies. The growth mechanism is generalized for rods, spindles, and nearly spherical nanostructures, obtained by varying the cation group in the quaternary ammonium hydroxides. Electron diffraction shows different predominant lattice planes on the edge and on the surface of a nanoplate. The study explains, hereto unaddressed, the temporal evolution of complex magnetic nanostructures. These ferromagnetic nanostructures represent an interesting combination of shape anisotropy and magnetic characteristics.

show abstract

Dipolar chains formed by chemically synthesized cobalt nanocubes

Cited by 12 publications

References 25 publications

Ionic Additives and Weak Magnetic Fields in the Thermal Decomposition of Octacarbonyldicobalt – Tools To Control the Morphology of Cobalt Nanoparticles

Ionic Additives and Weak Magnetic Fields in the Thermal Decomposition of Octacarbonyldicobalt – Tools To Control the Morphology of Cobalt Nanoparticles

Nanopartículas magnéticas: o cobalto

Formation and shape-control of hierarchical cobalt nanostructures using quaternary ammonium salts in aqueous media

Contact Info

Product

Resources

About