Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly

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Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly. / Malik, Vikash; Pal, Antara; Pravaz, Olivier; Crassous, Jerome; Granville, Simon; Grobety, Bernard; Hirt, Ann M; Dietsch, Hervé; Schurtenberger, Peter.

I: Nanoscale, Vol. 9, Nr. 38, 2017, s. 14405 – 14413.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

Malik, V, Pal, A, Pravaz, O, Crassous, J, Granville, S, Grobety, B, Hirt, AM, Dietsch, H & Schurtenberger, P 2017, 'Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly', Nanoscale, vol. 9, nr. 38, s. 14405 – 14413. https://doi.org/10.1039/C7NR04518B

APA

Malik, V., Pal, A., Pravaz, O., Crassous, J., Granville, S., Grobety, B., Hirt, A. M., Dietsch, H., & Schurtenberger, P. (2017). Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly. Nanoscale, 9(38), 14405 – 14413. https://doi.org/10.1039/C7NR04518B

CBE

Malik V, Pal A, Pravaz O, Crassous J, Granville S, Grobety B, Hirt AM, Dietsch H, Schurtenberger P. 2017. Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly. Nanoscale. 9(38):14405 – 14413. https://doi.org/10.1039/C7NR04518B

MLA

Vancouver

Malik V, Pal A, Pravaz O, Crassous J, Granville S, Grobety B et al. Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly. Nanoscale. 2017;9(38):14405 – 14413. https://doi.org/10.1039/C7NR04518B

Author

Malik, Vikash ; Pal, Antara ; Pravaz, Olivier ; Crassous, Jerome ; Granville, Simon ; Grobety, Bernard ; Hirt, Ann M ; Dietsch, Hervé ; Schurtenberger, Peter. / Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly. I: Nanoscale. 2017 ; Vol. 9, Nr. 38. s. 14405 – 14413.

RIS

TY - JOUR

T1 - Hybrid magnetic iron oxide nanoparticles with tunable field-directed self-assembly

AU - Malik, Vikash

AU - Pal, Antara

AU - Pravaz, Olivier

AU - Crassous, Jerome

AU - Granville, Simon

AU - Grobety, Bernard

AU - Hirt, Ann M

AU - Dietsch, Hervé

AU - Schurtenberger, Peter

PY - 2017

Y1 - 2017

N2 - We describe the synthesis of hybrid magnetic ellipsoidal nanoparticles that consist of a mixture of two different iron oxide phases, hematite (α-Fe2O3) and maghemite (γ-Fe2O3), and characterize their magnetic field-driven self-assembly. We demonstrate that the relative amount of the two phases can be adjusted in a continuous way by varying the reaction time during the synthesis, leading to strongly varying magnetic properties of the particles. Not only does the saturation magnetization increase dramatically as the composition of the spindles changes from hematite to maghemite, but also the direction of the induced magnetic moment changes from being parallel to the short axis of the spindle to being perpendicular to it. The magnetic dipolar interaction between the particles can be further tuned by adding a screening silica shell. Small-angle X-ray scattering (SAXS) experiments reveal that at high magnetic field, magnetic dipole–dipole interaction forces the silica coated particles to self-assemble into a distorted hexagonal crystal structure at high maghemite content. However, in the case of uncoated maghemite particles, the crystal structure is not very prominent. We interpret this as a consequence of the strong dipolar interaction between uncoated spindles that then become arrested during field-induced self-assembly into a structure riddled with defects.

AB - We describe the synthesis of hybrid magnetic ellipsoidal nanoparticles that consist of a mixture of two different iron oxide phases, hematite (α-Fe2O3) and maghemite (γ-Fe2O3), and characterize their magnetic field-driven self-assembly. We demonstrate that the relative amount of the two phases can be adjusted in a continuous way by varying the reaction time during the synthesis, leading to strongly varying magnetic properties of the particles. Not only does the saturation magnetization increase dramatically as the composition of the spindles changes from hematite to maghemite, but also the direction of the induced magnetic moment changes from being parallel to the short axis of the spindle to being perpendicular to it. The magnetic dipolar interaction between the particles can be further tuned by adding a screening silica shell. Small-angle X-ray scattering (SAXS) experiments reveal that at high magnetic field, magnetic dipole–dipole interaction forces the silica coated particles to self-assemble into a distorted hexagonal crystal structure at high maghemite content. However, in the case of uncoated maghemite particles, the crystal structure is not very prominent. We interpret this as a consequence of the strong dipolar interaction between uncoated spindles that then become arrested during field-induced self-assembly into a structure riddled with defects.

U2 - 10.1039/C7NR04518B

DO - 10.1039/C7NR04518B

M3 - Article

VL - 9

SP - 14405

EP - 14413

JO - Nanoscale

JF - Nanoscale

SN - 2040-3372

IS - 38

ER -