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We report the anomalous Nernst effect in trilayers containing a thin film of the half-metallic ferromagnetic Heusler alloy Co2Fe0.4Mn0.6Si with perpendicular magnetic anisotropy. The structure is MgO/CFMS/Pd and we have studied the variation of anomalous Hall and Nernst effects as a function of CFMS and Pd thickness. The anomalous Nernst coefficient reaches 0.5 μV/K at room temperature and we have observed a strong dependence of the anomalous Nernst coefficient on the thickness of both layers. Our results indicate that inducing perpendicular magnetic anisotropy in a strongly spin-polarising Heusler alloy such as CFMS is very promising for new thermoelectric devices based on exploiting the anomalous Nernst effect.

The field of magnon spintronics offers a charge current free way of information transportation by using spin waves (SWs). Compared to forward volume spin waves for example, Damon-Eshbach (DE) SWs need a relatively weak external magnetic field which is suitable for small spintronic devices. In this work we study DE SWs in Co 2 MnSi, a half-metallic Heusler alloy with significant potential for magnonics. Thin films have been produced by pulsed laser deposition. Integrated coplanar waveguide (CPW) antennas with different distances between emitter and detection antenna have been prepared on a Co 2 MnSi film. We used a vector network analyzer to measure spin wave reflection and transmission. We observe spin wave propagation up to 100 μm, a new record for half-metallic Heusler thin films.

In this paper, we investigate the characteristics of antenna for propagating-spin-wave-spectroscopy (PSWS) experiment in ferromagnetic thin films. Firstly, we simulate the amplitude and phase distribution of the high-frequency magnetic field around antenna by high frequency structure simulator (HFSS). And then k distribution of the antenna is obtained by fast Fourier transformation (FFT). Furthermore, three kinds of antenna designs, i.e. micro-strip line, coplanar waveguide (CPW), loop, are studied and compared. How the dimension parameter of antenna influence the corresponding high-frequency magnetic field amplitude and k distribution are investigated in details.

The resistance of the Pt bar deposited on the YIG slab was monitored while the magnetic field was ramped through the ferromagnetic resonance with the YIG slab facing a coplanar waveguide resonator excited at 4.3 GHz excitation. The resistance change provides detection of the ferromagnetic resonance with a high signal-to-noise ratio. It is ascribed to a change in the temperature of the Pt bars. The thermal origin of the signal is confirmed by the observation that the signal vanishes when field modulation is applied at frequencies above 6 Hz. The spin pumping effect was vanishingly small, and the anisotropic magnetoresistance of the Pt bar, though quite easily observed, would imply a rectification voltage that is much smaller than the bolometric effect.

The thermoelectric and transport properties of MgO/Co2MnGa/Pd stacks with perpendicular magnetic anisotropy were measured. For a nominal 3.3 nm Co2MnGa thickness, the anomalous Nernst coefficient and the Nernst angle at room temperature were found to be 0.3 ± 0.05 μV/K and 5 ± 1 % , respectively. The Nernst and Hall angle temperature dependences show similar trends. Increasing the Co2MnGa thickness to 3.6 nm enhances the anomalous Nernst angle to 6.5% at room temperature. At remanence, the anomalous Nernst coefficient at room temperature is half the saturation value.

Spin-dependent thermoelectric transport properties have been experimentally studied on a micro-structured device based on epitaxially grown 75-nm-thick Co2Ti0.6V0.4Sn0.75 Heusler film with integrated heater and thermometers. The anomalous Nernst coefficient is found to be 0.5 μV/K at 50 K. Thermoelectric power in both longitudinal and transverse directions have been measured with magnetic field rotated in-plane. Asymmetric peaks and valleys are observed at particular in-plane field angle around 25 K. These anomalous peaks show novel magnetic hysteresis due to the interplay between the magnetization and the temperature gradient. These complex behaviors of thermoelectric effect during magnetization reversal still need to be understood.