Ferromagnetic Resonance of Horse Spleen Ferritin: Core Blocking and Surface Ordering Temperatures

Wajnberg, Eliane; El-Jaick, Léa Jaccoud; Linhares, Marília Paixão; Esquivel, Darci M. S.

doi:10.1006/jmre.2001.2430

Cited by 49 publications

(48 citation statements)

References 25 publications

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“…3c). At 5 K we detect an increase of the resonance line width by roughly 5 MHz, which can be attributed to inhomogeneous broadening [6]. At 77 K the majority of the ferritin molecules fluctuate with a rate faster than the inverse microwave pulse length (500 ns), such that only the average magnetization of the molecular ensemble is detected.…”

Section: Techniquementioning

confidence: 78%

“…The obtained blocking temperatures can be compared to values reported for horse-spleen ferritin using other detection techniques; susceptibility measurements (characteristic measurement time τ m ∼ 10 −3 -10 2 s) yield blocking temperatures in the range 5-20 K [3,5,24,33], Mößbauer spectroscopy (τ m ∼ 10 −8 s) 30-50 K [5,22,23], and electron spin resonance spectroscopy (τ m ∼ 10 −10 s) ∼ 100 K [6]. Our findings using NV magnetometry are thus consistent with previously reported results.…”

Section: Techniquementioning

confidence: 91%

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Tracking Temperature-Dependent Relaxation Times of Ferritin Nanomagnets with a Wideband Quantum Spectrometer

et al. 2014

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We demonstrate the tracking of the spin dynamics of ensemble and individual magnetic ferritin proteins from cryogenic up to room temperature using the nitrogen-vacancy color center in diamond as magnetic sensor. We employ different detection protocols to probe the influence of the ferritin nanomagnets on the longitudinal and transverse relaxation of the nitrogen-vacancy center, which enables magnetic sensing over a wide frequency range from Hz to GHz. The temperature dependence of the observed spectral features can be well understood by the thermally induced magnetization reversals of the ferritin and enables the determination of the anisotropy barrier of single ferritin molecules. The study of magnetic fluctuations -time-dependent deviations of a magnetic system from equilibrium -is of high intrinsic interest and provides a powerful tool to gain insight into magnetic coupling mechanisms [1, 2]. Experimentally, however, access to fluctuations is frequently challenging, owing to two reasons: Firstly, fluctuations can extend over an excessively large range of frequencies. Secondly, many relevant magnetic systems are small entities with dimensions in the nanometer range, such as single molecules, clusters, or magnetic domains. Hence, the study of magnetic fluctuations requires a measurement technique featuring simultaneously nanoscale resolution and a wide frequency bandwidth.Widely used methods to study ensembles of magnetic nanosystems are SQUID magnetometry [3,4], Mößbauer spectroscopy [5], electron spin resonance [6], neutron scattering [7], or X-ray magnetic circular dichroism [8]. Furthermore, individual magnetic nano-objects have been investigated by scanning probe microscopy [9, 10], micro-SQUIDs [11,12] or scanning X-ray microscopy [13]. In general these techniques have a limited detection bandwidth, such that the experimental observation of magnetic fluctuations in a wide frequency range relies on stitched measurements combining complementary techniques in different frequency domains.Here we show that the Nitrogen-Vacancy (NV) center in diamond employed as a magnetic field sensor [14,15] simultaneously provides access to both nanoscale objects and a frequency bandwidth spanning ten orders of magnitude. We use the unique properties of the NV to monitor thermal magnetization reversals of single biological nano-magnets from cryogenic to room temperature where these fluctuations accelerate from the sub-Hz to the GHz range.We study ferritin protein complexes adsorbed onto a diamond surface (Fig. 1a). Each of these proteins en- closes a cluster of up to 4500 Fe atoms wich net magnetic moment exhibits strong thermally activated fluctuations. We detect the magnetic stray field of these clusters with NV defect centers embedded 5-10 nm below the diamond surface. This center enables the precise determination of the local magnetic field via the Zeeman shift of its spin sublevels, which can be measured by optically detected magnetic resonance (ODMR) techniques. Due to its atomic size, an individual NV center can be pl...

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Section: Techniquementioning

confidence: 78%

Section: Techniquementioning

confidence: 91%

Tracking Temperature-Dependent Relaxation Times of Ferritin Nanomagnets with a Wideband Quantum Spectrometer

et al. 2014

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“…Table 2 shows the values obtained, as well as KV and MV of nanoparticles of ferrihydrite of biogenic origin. The table also shows the corresponding parameters of ferritin complexes calculated from the temperature curves of FMR [15]. Figure 4 (curve 1) shows the Mossbauer spectrum of chemically prepared ferrihydrite nanoparticles, characterized by a paramagnetic doublet.…”

Section: Resultsmentioning

confidence: 99%

Preparation, structure and magnetic properties of synthetic ferrihydrite nanoparticles

Stolyar

Yaroslavtsev

Bayukov

et al. 2018

J. Phys.: Conf. Ser.

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“…These functions are determined as follows: Table 6 presents the obtained values of these fitting parameters, as well as the parameters KV and MV for ferrihydrite nanoparticles of biogenic origin, for which the resonance curves were reported in [20]. This table also presents the corresponding parameters for ferritin complexes, which were calcu-3 lated from the temperature dependences of the ferromagnetic resonance [23].…”

Section: Results Of the Ferromagnetic Resonance (Fmr)mentioning

confidence: 99%

Magnetic and resonance properties of ferrihydrite nanoparticles doped with cobalt

et al. 2017

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Abstract-Powders of undoped ferrihydrite nanoparticles and ferrihydrite nanoparticles doped with cobalt in the ratio of 5 : 1 have been prepared by hydrolysis of 3d-metal salts. It has been shown using Mössbauer spectroscopy that cobalt is uniformly distributed over characteristic crystal-chemical positions of iron ions. The blocking temperatures of ferrihydrite nanoparticles have been determined. The nanoparticle sizes, magnetizations, surface anisotropy constants, and bulk anisotropy constants have been estimated. The doping of ferrihydrite nanoparticles with cobalt leads to a significant increase in the anisotropy constant of a nanoparticle and to the formation of surface rotational anisotropy with the surface anisotropy constant K u = 1.6 × 10 -3 erg/cm 2 .

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Ferromagnetic Resonance of Horse Spleen Ferritin: Core Blocking and Surface Ordering Temperatures

Cited by 49 publications

References 25 publications

Tracking Temperature-Dependent Relaxation Times of Ferritin Nanomagnets with a Wideband Quantum Spectrometer

Tracking Temperature-Dependent Relaxation Times of Ferritin Nanomagnets with a Wideband Quantum Spectrometer

Preparation, structure and magnetic properties of synthetic ferrihydrite nanoparticles

Magnetic and resonance properties of ferrihydrite nanoparticles doped with cobalt

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