Electron transport and the effect of current annealing in a two-point contacted hBN/graphene/hBN heterostructure device
In this work, we fabricated a 2D van der Waals heterostructure device in an inert nitrogen atmosphere by means of a dry transfer technique in order to obtain a clean and largely impurity free stack of hexagonal boron nitride (hBN)-encapsulated few-layer graphene. The heterostructure was contacted from the top with gold leads on two sides, and the device’s properties including intrinsic charge carrier density, mobility, and contact resistance were studied as a function of temperature from 4 K to 270 K. We show that the contact resistance of the device mainly originates from the metal/graphene interface, which contributes a significant part to the total resistance. We demonstrate that current…
Strain-induced Shape Anisotropy in Antiferromagnetic Structures
We demonstrate how shape dependent strain can be used to control antiferromagnetic order in NiO Pt thin films. For rectangular elements patterned along the easy and hard magnetocrystalline anisotropy axes of our film, we observe different domain structures and we identify magnetoelastic interactions that are distinct for different domain configurations. We reproduce the experimental observations by modeling the magnetoelastic interactions, considering spontaneous strain induced by the domain configuration, as well as elastic strain due to the substrate and the shape of the patterns. This allows us to demonstrate and explain how the variation of the aspect ratio of rectangular elements can b…
Impact of Annealing Temperature on Tunneling Magnetoresistance Multilayer Stacks
The effect of annealing temperatures on the tunnel magnetoresistance (TMR) of MgO-based magnetic tunnel junctions (MTJs) has been investigated for annealing between 190 and 370°C. The TMR shows a maximum value of 215% at an annealing temperature of 330°C. A strong sensitivity of the TMR and the exchange bias of the pinned ferromagnetic layers on the annealing temperature are observed. Depending on sensor application requirements, the MTJ can be optimized either for stability and pinning strength or for a high TMR signal by choosing the appropriate annealing temperature. The switching mechanism of the ferromagnetic layers in the MTJ and the influence of the annealing on the layer properties,…
Data for the article "Strain-induced shape anisotropy in antiferromagnetic structures"
Data for the article "Strain-induced shape anisotropy in antiferromagnetic structures" URL: https://link.aps.org/doi/10.1103/PhysRevB.106.094430 DOI: 10.1103/PhysRevB.106.094430