Niclas Teichert

Heusler nanoparticles for spintronics and ferromagnetic shape memory alloys

Heusler nanoparticles emerge as a new class of multifunctional materials. In this critical review, the latest progress in studies on Heusler nanoparticles is summarized. The authors discuss their structural and physical properties interesting for research fields such as spintronics and ferromagnetic shape memory alloys. As a young research field, the majority of studies on Heusler nanoparticles focus on their synthesis, structure, and magnetic characterizations. Important issues such as size dependent structure, phase transition, magnetic, and spin-related properties are still open. Further investigations are needed to verify the technical significance of Heusler nanoparticles for practical applications such as data storage, magnetic sensors, and microactuators.

Thickness dependent exchange bias in martensitic epitaxial Ni-Mn-Sn thin films

A thickness dependent exchange bias in the low temperature martensitic state of epitaxial Ni-Mn-Sn thin films is found. The effect can be retained down to very small thicknesses. For a Ni50Mn32Sn18 thin film, which does not undergo a martensitic transformation, no exchange bias is observed. Our results suggest that a significant interplay between ferromagnetic and antiferromagnetic regions, which is the origin for exchange bias, is only present in the martensite. The finding is supported by ab initio calculations showing that the antiferromagnetic order is stabilized in the phase.

Exchange bias effect in martensitic epitaxial Ni-Mn-Sn thin films applied to pin CoFeB/MgO/CoFeB magnetic tunnel junctions

The exchange bias effect is commonly used to shift the coercive field of a ferromagnet. This technique is crucial for the use of magnetic tunnel junctions as logic or memory devices. Therefore, an independent switching of the two ferromagnetic electrodes is necessary to guarantee a reliable readout. Here, we demonstrate that the intrinsic exchange bias effect of Ni-Mn-Sn can be used to apply a unidirectional anisotropy to magnetic tunnel junctions. For this, we use epitaxial Ni-Mn-Sn films as pinning layers for microfabricated CoFeB/MgO/CoFeB magnetic tunnel junctions. We compare the exchange bias field (

Structure and giant inverse magnetocaloric effect of epitaxial Ni-Co-Mn-Al films

H_{\text{EB}}

Role of disorder when upscaling magnetocaloric Ni–Co–Mn–Al Heusler alloys from thin films to ribbons

) measured after field cooling in

How to enable bulk-like martensitic transformation in epitaxial films

-10

Heusler Compounds Go Nano

\,kOe external field by magnetization measurements with

Structural, magnetic, and electrical properties of perpendicularly magnetized Mn4–xFexGe thin films

H_{\text{EB}}

Pb arachidate Langmuir-Blodgett coatings of silicon wafers: relation between Pb particle density and subphase composition

obtained from tunnel magnetoresistance measurements. Consistent for both methods we find an exchange bias of about

Electrical transport and optical band gap of NiFe2Ox thin films

H_{\text{EB}}=130