Tailoring Staircase-like Hysteresis Loops in Electrodeposited Trisegmented Magnetic Nanowires: a Strategy toward Minimization of Interwire Interactions

Zhang, Jin; Agramunt-Puig, Sebastià; Del-Valle, Núria; Navau, Carles; Baró, María Dolors; Estradé, S.; Peiró, Francesca; Pané, Salvador; Nelson, Bradley J.; Sanchez, Alvaro; Nogués, J.; Pellicer, Eva; Sort, Jordi

doi:10.1021/acsami.5b11747

Cited by 26 publications

(25 citation statements)

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“…1,2 Indeed, these interactions are key to the performance of many common magnetic materials, e.g., permanent magnets, 3,4 magnetic recording media, 5,6 magnetically soft materials for high frequency ap-plications, 7 where dipolar interactions may have undesirable effects, such as aggregation of nanoparticles in biomedical applications. [8][9][10] Magnetic interactions control the properties of sufficiently dense assemblies of magnetic nanoparticles and nanostructures, tailoring their functional properties, e.g., blocking (or freezing) temperature, coercivity, remanent magnetization, switching-field distribution and effective anisotropy, among others. [11][12][13][14][15][16] In fact, interactions are the basis of a large number of nanoparticle-based magnetic materials, e.g., superferromagnets, superspin glasses, artificial spin ice, long range self-assemblies, or ferrofluids.…”

Section: Introductionmentioning

confidence: 99%

Remanence Plots as a Probe of Spin Disorder in Magnetic Nanoparticles

et al. 2017

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Remanence magnetization plots (e.g., Henkel or δM plots) have been extensively used as a straightforward way to determine the presence and intensity of dipolar and exchange interactions in assemblies of magnetic nanoparticles or single domain grains.Their evaluation is particularly important in functional materials whose performance is strongly affected by the intensity of interparticle interactions, such as patterned recording media and nanostructured permanent magnets, as well as in applications such as hyperthermia and magnetic resonance imaging. Here we demonstrate that δM plots may be misleading when the nanoparticles do not have a homogeneous internal magnetic configuration. Substantial dips in the δM plots of γ-Fe 2 O 3 nanoparticles isolated by thick SiO 2 shells indicate the presence of demagnetizing interactions, usually identified as dipolar interactions. Our results, however, demonstrate that it is the inhomogeneous spin structure of the nanoparticles, as most clearly evidenced by Mössbauer measurements, that has a pronounced effect on the δM plots, leading to features remarkably similar to those produced by dipolar interactions. X-ray diffraction results combined with magnetic characterization indicate that this inhomogeneity is due to the presence of surface structural (and spin) disorder. Monte Carlo simulations unambiguously corroborate the critical role of the internal magnetic structure in the δM plots. Our findings constitute a cautionary tale on the widespread use of remanence plots to assess interparticle interactions, as well as offer new perspectives in the use of Henkel-and δM-plots to quantify the rather elusive inhomogeneous magnetizations states in nanoparticles.Additional information on the δM and the in-field Mössbauer techniques, table with the complete results of the Mössbauer spectra fits, details of the Monte Carlo simulations, FC and ZFC magnetization curves of the VST series (Fig. S1a), Langevin scaling of M(H;T) data measured in VST45 (Fig. S1b), details on the estimate of the "magnetic size" from Langevin fits, δM plots of all the VST series and graphical analysis of the intraparticle and interparticle contributions to the dip (Fig. S2), example of hysteresis loops measured after ZFC and FC (for sample VST17, Fig. S3); X-ray diffraction patterns and lattice parameter across of the maghemite cores of different size (Fig. S4); complete results from Monte Carlo simulations showing the dependence of δM on core anisotropy (Fig. S5), surface anisotropy ( Fig. S6), exchange coupling constant ( Fig. S7) and disordered surface thickness (Fig. S8).

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Section: Introductionmentioning

confidence: 99%

Remanence Plots as a Probe of Spin Disorder in Magnetic Nanoparticles

et al. 2017

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“…The magnetic properties of arrays of nanowires deposited inside the pores of oxide templates (AAO or TiO 2 ) have been widely investigated for applications like high-density recording media [48], giant magneto-resistance [137] or magnetic control of biomolecule desorption [138], among others. Eventually, polymeric porous templates (e.g., nanoporous polycarbonate membranes) have been utilized, in cases where the use of oxide membranes was found to be not compatible with the electrolytic bath and deposition conditions [139,140]. The investigated magnetic materials comprise single metals (like Fe, Co or Ni) [11,48,51,[141][142][143][144], binary (Co-W, Co-Pt, CoNi, FeNi, etc.)…”

Section: Magnetic Properties Of Nanowiresmentioning

confidence: 99%

Electrodeposition of Iron-Group Alloys into Nanostructured Oxide Membranes: Synthetic Challenges and Properties

Cesiulis

Tsytsaru

Podlaha

et al. 2018

CNANO

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Background: Quasi-one dimensional nanostructures: nanowires, nanotubes, nanorods, nanobelts/nanoribbons and complex "nanowire-nanoparticle" composites have been synthesized over the years. These nanostructures are particularly appealing due to their specific properties defined by their high aspect ratio: two dimensions are in the nanoscale range and one dimension is in the microscale. Methods:One of the well-designed approaches for the synthesis of such nanostructured materials is template-assisted fabrication combined with electrodeposition. The fabrication approaches for the growth of iron-group alloy nanostructures inside nanoporous oxide membranes by means of different electrodeposition techniques, and the resulting unique properties and potential applications of this type of materials are reviewed. Results:Arrays of nanostructures can be obtained by filling a porous oxide template that contains a large number of straight cylindrical, nano-sized diameter holes. Generalities of metals electrodeposition into nanoporous oxide membranes are discussed. Measures to minimize the nonuniformity of deposits inside pores need to be addressed to thin the barrier layer, to control hydrogen evolution and to improve mass transport inside the pores. Examples of binary and ternary iron group alloys grown inside nanoporous oxide templates are provided. Catalytic hydrogen evolution and methanol oxidation on the nanowires arrays are described. The "sample size effect" on the magnetic properties of materials and the electrodeposition of multilayered structures necessary for giant magnetoresistance (GMR) are discussed in details. Conclusion:Electrodeposition of binary and ternary iron-group alloys confirm that controlling alloy composition inside nanopores is still a challenge. composites [7] have been synthesized over the years. These nanostructures are particularly appealing due to their specific properties defined by their high aspect ratio: two dimensions are in the nanoscale range and one dimension is in the microscale. One of the well-designed approaches for the synthesis of such nanostructured materials is template-assisted fabrication combined with electrodeposition, first reported by Possin [8] in track etched mica films, and expanded upon by others with different materials and templates [2,[9][10][11][12][13][14]. However, the self-organized porous anodic aluminum oxide (AAO) membrane has become one of the most often used templates for tunable synthesis of different nanostructured materials [15,16].

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“…The first method allows for minimizing the co-deposition phenomenon that is present when different metallic ions can be electrodeposited at similar values of the deposition potential within each segment at the same time. Therefore, a purer chemical composition in each segment of the NW can be achieved in this way [31,35,36]. This synthesis procedure of subsequent segmented magnetic NWs can also lead to poor adhesion between layers with different chemical compositions, or uneven morphological growth, due to changes in the crystalline structure of the respective segments [37] but, at the same time, the assembling building blocks of consecutive segments of the NW having different material composition with a well-defined interface layer at the junctions, which can act as a pinning center for the magnetic domain wall's displacement along the wire length.…”

Section: Introductionmentioning

confidence: 99%

Ni-Co Alloy and Multisegmented Ni/Co Nanowire Arrays Modulated in Composition: Structural Characterization and Magnetic Properties

et al. 2017

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Design of novel multisegmented magnetic nanowires can pave the way for the next generation of data storage media and logical devices, magnonic crystals, or in magneto-plasmonics, among other energy conversion, recovery, and storage technological applications. In this work, we present a detailed study on the synthesis, morphology, structural, and magnetic properties of Ni, Co, and Ni-Co alloy and multisegmented Ni/Co nanowires modulated in composition, which were grown by template-assisted electrodeposition employing nanoporous anodic aluminum oxide as patterned templates. X-ray diffraction, and scanning and high-resolution transmission electron microscopies allowed for the structural, morphological, and compositional investigations of a few micrometers long and approximately 40 nm in diameter of pure Ni and Co single elements, together with multisegmented Ni/Co and alloyed Ni-Co nanowires. The vibrating sample magnetometry technique enabled us to extract the main characteristic magnetic parameters for these samples, thereby evaluating their different anisotropic magnetic behaviors and discuss them based on their morphological and structural features. These novel functional magnetic nanomaterials can serve as potential candidates for multibit magnetic systems in ultra-high-density magnetic data storage applications.

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Tailoring Staircase-like Hysteresis Loops in Electrodeposited Trisegmented Magnetic Nanowires: a Strategy toward Minimization of Interwire Interactions

Cited by 26 publications

References 50 publications

Remanence Plots as a Probe of Spin Disorder in Magnetic Nanoparticles

Remanence Plots as a Probe of Spin Disorder in Magnetic Nanoparticles

Electrodeposition of Iron-Group Alloys into Nanostructured Oxide Membranes: Synthetic Challenges and Properties

Ni-Co Alloy and Multisegmented Ni/Co Nanowire Arrays Modulated in Composition: Structural Characterization and Magnetic Properties

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