TY - JOUR

T1 - Superparamagnetic behaviour of metallic Co nanoparticles according to variable temperature magnetic resonance

AU - Yakovlev, Ilya V.

AU - Yakushkin, Stanislav S.

AU - Kazakova, Mariya A.

AU - Trukhan, Sergey N.

AU - Volkova, Zoya N.

AU - Gerashchenko, Alexander P.

AU - Andreev, Andrey S.

AU - Ishchenko, Arcady V.

AU - Martyanov, Oleg N.

AU - Lapina, Olga B.

AU - d’Espinose de Lacaillerie, Jean Baptiste

N1 - Funding Information: The reported study was funded by RFBR, according to the research project No. 20-33-90184. O. B. L. acknowledged the budget project of Boreskov Institute of Catalysis. I. V. Y. acknowledged the French Embassy in Moscow for a Vernadski PhD fellowship. Z. N. V. and A. P. G. acknowledge the funding within the state assignment of Ministry of Science and Higher Education of Russian Federation (no. AAAA-A19-119012990095-0). Pascal Scholzen (ESPCI Paris) is thanked for rich discussions on 59Co IF NMR. Funding Information: The reported study was funded by RFBR, according to the research project No. 20-33-90184. O. B. L. acknowledged the budget project of Boreskov Institute of Catalysis. I. V. Y. acknowledged the French Embassy in Moscow for a Vernadski PhD fellowship. Z. N. V. and A. P. G. acknowledge the funding within the state assignment of Ministry of Science and Higher Education of Russian Federation (no. AAAA-A19-119012990095-0). Pascal Scholzen (ESPCI Paris) is thanked for rich discussions on59Co IF NMR. Publisher Copyright: © the Owner Societies 2021. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/1/28

Y1 - 2021/1/28

N2 - Investigating the size distributions of Co nanoparticle ensembles is an important problem, which has no straightforward solution. In this work, we use the combination of59Co internal field nuclear magnetic resonance (59Co IF NMR) and ferromagnetic resonance (FMR) spectroscopies on a metallic Co nanoparticle sample with a narrow Co nanoparticle size distribution due to encapsulation within the inner channels of carbon nanotubes. High-resolution transmission electron microscopy (TEM) images showed that the nanoparticles can be represented as prolate spheroids, with the majority of particles having an aspect ratio between 1 and 2. This observation has increased the accuracy of superparamagnetic blocking size calculations from Néel relaxation model by introducing the actual volume of the ellipsoids taken from the image processing.59Co IF NMR and FMR experiments conducted under different temperatures allowed us to observe the thermal blocking of superparamagnetic particles in full accordance with the TEM particle volume distribution. This proved that these magnetic resonance techniques can be used jointly for characterization of Co nanoparticles in the bulk of the sample.

AB - Investigating the size distributions of Co nanoparticle ensembles is an important problem, which has no straightforward solution. In this work, we use the combination of59Co internal field nuclear magnetic resonance (59Co IF NMR) and ferromagnetic resonance (FMR) spectroscopies on a metallic Co nanoparticle sample with a narrow Co nanoparticle size distribution due to encapsulation within the inner channels of carbon nanotubes. High-resolution transmission electron microscopy (TEM) images showed that the nanoparticles can be represented as prolate spheroids, with the majority of particles having an aspect ratio between 1 and 2. This observation has increased the accuracy of superparamagnetic blocking size calculations from Néel relaxation model by introducing the actual volume of the ellipsoids taken from the image processing.59Co IF NMR and FMR experiments conducted under different temperatures allowed us to observe the thermal blocking of superparamagnetic particles in full accordance with the TEM particle volume distribution. This proved that these magnetic resonance techniques can be used jointly for characterization of Co nanoparticles in the bulk of the sample.

UR - http://www.scopus.com/inward/record.url?scp=85100592642&partnerID=8YFLogxK

U2 - 10.1039/d0cp05963c

DO - 10.1039/d0cp05963c

M3 - Article

C2 - 33492314

AN - SCOPUS:85100592642

VL - 23

SP - 2723

EP - 2730

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 4

ER -