Numerical simulations of quasistatic remagnetization processes in fine magnetic particle systems

In this review article, we conceptually investigated the requirements of magnetic nanoparticles for their application in biosensing and related them to example systems of our thin-film portfolio. Analyzing intrinsic magnetic properties of different magnetic phases, the size range of the magnetic particles was determined, which is of potential interest for biosensor technology. Different e-beam lithography strategies are utilized to identify possible ways to realize small magnetic particles targeting this size range. Three different particle systems from 500 μm to 50 nm are produced for this purpose, aiming at tunable, vertically magnetized synthetic antiferromagnets, martensitic transformation in a single elliptical, disc-shaped Heusler Ni50Mn32.5Ga17.5 particle and nanocylinders of Co2MnSi-Heusler compound. Perspectively, new applications for these particle systems in combination with microfluidics are addressed. Using the concept of a magnetic on–off ratchet, the most suitable particle system of these three materials is validated with respect to magnetically-driven transport in a microfluidic channel. In addition, options are also discussed for improving the magnetic ratchet for larger particles.

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Uniform-in-time error estimate of the random batch method for the Cucker–Smale model

Mathematical Models and Methods in Applied Sciences ◽

10.1142/s0218202521400029 ◽

2021 ◽

pp. 1-37

Author(s):

Seung-Yeal Ha ◽

Shi Jin ◽

Doheon Kim ◽

Dongnam Ko

Keyword(s):

Error Estimate ◽

Numerical Simulations ◽

Decay Rate ◽

Interacting Particle Systems ◽

Original System ◽

Contraction Semigroup ◽

Particle Systems ◽

Time Error ◽

Batch Method ◽

Interacting Particle

We present a uniform-in-time (and in particle numbers as well) error estimate for the random batch method (RBM) [S. Jin, L. Li and J.-G. Liu, Random batch methods (RBM) for interacting particle systems, J. Comput. Phys. 400 (2020) 108877] to the Cucker–Smale (CS) model. The uniform-in-time error estimates of the RBM have been obtained for various interacting particle systems, when corresponding flow generates a contraction semigroup. In this paper, we derive a uniform-in-time error estimate for RBM-approximation to the CS model in which the corresponding flow does not generate contractive semigroup. To derive uniform error estimate, we use asymptotic flocking estimate of the RBM-approximated CS model which yields the decay of relative velocities to zero, at least in the order of [Formula: see text], while velocities of the original system decay exponentially. Here, [Formula: see text] is the decay rate of the communication weight with respect to the distance between particles in the CS model. We also provide several numerical simulations to confirm the analytical results.

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An all white magnet by combination of electronic properties of a white light emitting MOF with strong magnetic particle systems

Journal of Materials Chemistry C ◽

10.1039/d0tc03473h ◽

2020 ◽

Vol 8 (45) ◽

pp. 16010-16017

Author(s):

Marcel T. Seuffert ◽

Susanne Wintzheimer ◽

Maximilian Oppmann ◽

Tim Granath ◽

Johannes Prieschl ◽

...

Keyword(s):

Electronic Properties ◽

White Light ◽

Magnetic Particle ◽

Light Emission ◽

Particle System ◽

Particle Systems ◽

White Light Emission ◽

Light Emitting ◽

Microscopic Scale ◽

Component Particle

A multi-component particle system was developed that combines the properties of white color, white light emission and strong magnetism on the macroscopic and microscopic scale.

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