Co-doped MnFe₂O₄ nanoparticles: magnetic anisotropy and interparticle interactions

• Bagher Aslibeiki,
• Parviz Kameli,
• Hadi Salamati,
• Giorgio Concas,
• Maria Salvador Fernandez,
• Alessandro Talone,
• Giuseppe Muscas and
• Davide Peddis

Beilstein J. Nanotechnol. 2019, 10, 856–865, doi:10.3762/bjnano.10.86

• progressive steps up to 5 T. In DCD measurements, the samples were cooled down to 5 K and then saturated by applying an external field of −5 T for a few seconds. Then, the remanent magnetization (MDCD) was measured such as in the IRM protocol increasing the field up to +5 T. AC magnetic susceptibility

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• Academy of Sciences, H-1525, Budapest, P. O. Box 49, Hungary Institute of Molecular Physics, Polish Academy of Sciences, 60179, Poznan, Poland 10.3762/bjnano.8.251 Abstract We report on experimental studies focusing on the dynamic ac magnetic susceptibility of a ferronematic. It has been shown recently

• , that in the isotropic phase of a ferronematic, a weak dc bias magnetic field of a few oersteds increases the ac magnetic susceptibility. This increment vanishes irreversibly if the substance is cooled down to the nematic phase, but can be reinduced by applying the dc bias field again in the isotropic

• saturation can be increased by about two orders of magnitude. This finding paves a way to application possibilities, such as low magnetic field sensors, or basic logical elements for information storage. Keywords: ac magnetic susceptibility; ferronematics; magnetic particles; Introduction The great

Microwave synthesis of high-quality and uniform 4 nm ZnFe₂O₄ nanocrystals for application in energy storage and nanomagnetics

• Christian Suchomski,
• Ben Breitung,
• Ralf Witte,
• Michael Knapp,
• Sondes Bauer,
• Tilo Baumbach,
• Christian Reitz and
• Torsten Brezesinski

Beilstein J. Nanotechnol. 2016, 7, 1350–1360, doi:10.3762/bjnano.7.126

• magnetic susceptibility measurements were carried out. We note that single-domain particle ensembles, in which interparticle interactions are non-negligible, are referred to as superspin glasses in the following [38][39]. The amplitude of the AC field was set to µ0HAC = 0.35 mT and the driving frequency, ν

• . Upon further cooling, the FC curve diverges from the ZFC curve and the material exhibits ferrimagnetic behavior. To determine whether Tmax can be associated with either a freezing temperature, Tf, for spin glasses or a blocking temperature, TB, for superparamagnetic particles, frequency-dependent AC

Phenalenyl-based mononuclear dysprosium complexes

• Yanhua Lan,
• Andrea Magri,
• Olaf Fuhr and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 995–1009, doi:10.3762/bjnano.7.92

• 74.29(11). Absorption spectra of the three dysprosium complexes in diluted (2 × 10−6 M) DMSO solutions of 1–4 at room temperature. (Top) Temperature dependence of out-of-phase component of ac magnetic susceptibility under zero dc field. (Middle) Frequency dependence of out-of-phase component of ac

• magnetic susceptibility under zero dc field. (Bottom) Arrhenius semi-log plots of the relaxation time, τ vs 1/T from ac susceptibility measurements under a zero dc field and applied dc field. The solid lines represent a linear fit in the thermally activated range of temperature. The parameters are

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• complex 5 has a sharp increase at μ0H = 0, indicative of a very fast tunneling rate of magnetization in this complex. This fact is in agreement with the AC magnetic susceptibility measurements discussed in the earlier section, where the fast tunneling can be slowed down as soon as a small field is applied

Spin relaxation in antiferromagnetic Fe–Fe dimers slowed down by anisotropic Dy^III ions

• Valeriu Mereacre,
• Frederik Klöwer,
• Yanhua Lan,
• Rodolphe Clérac,
• Juliusz A. Wolny,
• Volker Schünemann,
• Christopher E. Anson and
• Annie K. Powell

Beilstein J. Nanotechnol. 2013, 4, 807–814, doi:10.3762/bjnano.4.92

• (at 1500 Hz), which is characteristic of a slow relaxation of the magnetization (Figure 5). The characteristic measuring time for Mössbauer spectroscopy is about 10−7 s, whereas that for ac magnetic susceptibility measurements is typically in the range between 100 and 10−4 s (i.e., ac frequencies of 1

• –1500 Hz). Because of their different time windows, 57Fe Mössbauer spectroscopy and ac magnetic susceptibility measurements provide an apparently different view of the relaxation dynamic: If a slow relaxation can be seen in the magnetic data at very low temperatures (1.8–3.0 K), then an intermediate