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We calculate the orbital magnetization of a confined 2DEG as a function of the number of electrons in the system. Size effects are investigated by systematically increasing the area of the confining region. The results for the finite system…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Sigurdur I. Erlingsson , Andrei Manolescu , Vidar Gudmundsson

The magnetoresistance of a granular superconductor in a strong magnetic field is considered. It is assumed that this field destroys the superconducting gap in each grain, such that all interesting effects considered in the paper are due to…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 I. S. Beloborodov , K. B. Efetov , A. I. Larkin

The field dependence of the vortex core size $\xi(B)$ is incorporated in the London model, in order to describe reversible magnetization $M(B,T)$ for a number of materials with large Ginzburg-Landau parameter $\kappa$. The dependence…

For two decades, NdFeB based magnets have been a critical component in a range of electrical devices engaged in energy production and conversion. The magnet shape and the internal microstructure of the selected NdFeB grade govern their…

Instrumentation and Detectors · Physics 2016-11-17 J. Jacimovic , F. Binda , L. G. Herrmann , F. Greuter , J. Genta , M. Calvo , T. Tomse , R. A. Simon

We prepared epitaxial ferromagnetic manganite films on bicrystal substrates by pulsed laser ablation. Their low- and high-field magnetoresistance (MR) was measured as a function of magnetic field, temperature and current. At low…

Strongly Correlated Electrons · Physics 2009-10-31 W. Westerburg , F. Martin , S. Friedrich , M. Maier , G. Jakob

The present article reports a method for the average grain size evaluation of superconducting nano-particles through their magnetic properties. The use of SQUID magnetometry to determine the average MgB2 particle size was investigated and…

We have observed room temperature ferromagnetism (FM) in In$_2$O$_3$ thin films doped with either 5 at.% Mn or Fe, prepared by pulsed laser deposition (PLD) at substrate temperatures ranging from 300 to 600$\,^{\circ}{\rm C}$. The…

Materials Science · Physics 2013-05-22 Qi Feng , Harry J Blythe , A Mark Fox , Gillian A Gehring , Feng-Xian Jiang , Xiao-Hong Xu , Steve M Heald

The problem of finite size effects in s=1/2 Ising systems showing slow dynamics of the magnetization is investigated introducing diamagnetic impurities in a Co$^{2+}$-radical chain. The static magnetic properties have been measured and…

Mesoscale and Nanoscale Physics · Physics 2011-04-21 L. Bogani , A. Caneschi , M. Fedi , D. Gatteschi , M. Massi , M. A. Novak , M. G. Pini , A. Rettori , R. Sessoli , A. Vindigni

The Nd permanent magnet (Nd$_{2}$Fe$_{14}$B) is an indispensable material used in modern energy conversion devices. The realization of high coercivity at finite temperatures is a burning issue. One of the important ingredients for…

Materials Science · Physics 2021-01-20 Masamichi Nishino , Ismail Enes Uysal , Seiji Miyashita

We have observed a superparamagnetic to ferromagnetic transition in films of isolated Ni grains covered by non-magnetic overlayers. The magnetoresistance (MR) of the films was measured as a function of the overlayer thickness. Initially,…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. Frydman , R. C. Dynes

The thermal remagnetization (TR), i.e. the reentrance of magnetization upon heating in a steady-field demagnetized sample, is a common feature to the four types of polycrystalline permanent magnets, mainly utilized for practical purposes,…

Materials Science · Physics 2007-05-23 R. Schumann , L. Jahn

Co2FeAl (CFA) nanoparticles (NPs) of different sizes were synthesized by chemical route. The effect of the size of NPs upon the structure and magnetization compared to its bulk counterpart was investigated. The structure and composition…

Strongly Correlated Electrons · Physics 2019-10-01 Aquil Ahmad , Srimanta Mitra , S. K. Srivastava , A. K. Das

According to the classical laws of magnetism, the shape of magnetically soft objects limits the effective susceptibility. For example, spherical soft magnets cannot display an effective susceptibility larger than 3. Although this is true…

Mesoscale and Nanoscale Physics · Physics 2026-03-02 Mathias Zambach , Miriam Varón , Mads R. Almind , Matti Knaapila , Ziwei Ouyang , Marco Beleggia , Cathrine Frandsen

We report the particle size dependent magnetic behaviour in the antiferromagnetic spinel CoRh2O4. The nanoparticles were obtained by mechanical milling of bulk material, prepared under sintering method. The XRD spectra show that the samples…

Disordered Systems and Neural Networks · Physics 2007-05-23 R. N. Bhowmik , R. Nagarajan , R. Ranganathan

Magnetization of antiferromagnetic nanoparticles is known to generally scale up inversely to their diameter (d) according to N\'eel's model. Here we report a deviation from this conventional linear 1/d dependence, altered significantly by…

Frequency dependant complex magnetic permeability is used to understand RF-microwave behaviour of magnetic nanoparticles in the frequency range 250 MHz to 3 GHz. The stable dispersions of Fe3O4 nanoparticles with mean size varying between…

Applied Physics · Physics 2023-07-19 Mudra Jadav , S. P. Bhatnagar

Random sets with long-range dependence can be generated using a Boolean model with power-law grain sizes. We study thinnings of such Boolean models which have the hard-core property that no grains overlap in the resulting germ-grain model.…

Probability · Mathematics 2016-12-26 Mikko Kuronen , Lasse Leskelä

The static and dynamic properties of the single-chain molecular magnet [Co(hfac)$_2$NITPhOMe] are investigated in the framework of the Ising model with Glauber dynamics, in order to take into account both the effect of an applied magnetic…

Materials Science · Physics 2015-05-28 M. G. Pini , A. Rettori , L. Bogani , A. Lascialfari , M. Mariani , A. Caneschi , R. Sessoli

A novel method for controlling nanowire magnetic properties and growth from filling time profile is presented. The wires are grown with an electrodeposition method ("Template synthesis") with a wide selection of pore diameters. We show that…

Materials Science · Physics 2016-09-08 A. Ghaddar , F. Gloaguen , J. Gieraltowski

The coercive field of permanent magnets decays with temperature. At non-zero temperature the system can overcome a finite energy barrier through thermal fluctuations. Using finite element micromagnetic simulations, we quantify this effect,…

Materials Science · Physics 2016-03-29 Simon Bance , Johann Fischbacher , Alexander Kovacs , Harald Oezelt , Franz Reichel , Thomas Schrefl