Anomalous Nernst effect in Co₂MnSi thin films

Abstract

Separation of the anomalous Nernst and spin Seebeck voltages in bilayer devices is often problematic when both layers are metallic, and the anomalous Nernst effect (ANE) becomes non-negligible. Co2MnSi, a strong candidate for the spin generator in spin Seebeck devices, is a predicted half-metal with 100% spin polarisation at the Fermi energy, however, typically B2 or L21 order is needed to achieve this. We demonstrate the optimisation of thin film growth of Co2MnSi on glass, where choice of deposition and annealing temperature can promote various ordered states. The contribution from the ANE is then investigated to inform future measurements of the spin Seebeck. A maximum ANE coefficient of 0.662 µV K−1 is found for an A2 disordered polycrystalline Co2MnSi film. This value is comparable to ordered Heusler thin films deposited onto single crystal substrates but obtained at a far lower fabrication temperature and material cost.

Anomalous Nernst Effect in Flexible Co-Based Amorphous Ribbons

“…This value is smaller than that of one observer for the NR ribbon, a feature associated with the modification in the electrical resistivity of the ribbon after the annealing. The reached for our flexible Co-based ribbons are compared with similar systems produced in thin films deposited onto rigid substrates [ 57 , 58 ].…”

Longitudinal Spin Seebeck Effect Thermopiles Based on Flexible Co-Rich Amorphous Ribbons/Pt Thin-Film Heterostructures

“…Furthermore, the flexibility of these materials in combination with the corrosion stability of Cr-doped compositions makes them promising candidates for sensor applications, particularly for covering of the curved surfaces or surfaces having even more complex geometry. All these features are interesting for thermoelectric applications based on the Longitudinal Spin Seebeck Effect (LSSE) [ 11 , 12 , 13 ] and Anomalous Nernst Effect (ANE) [ 14 , 15 , 16 , 17 ].…”