Large Thermo-Spin Effects in Heusler Alloy-Based Spin Gapless Semiconductor Thin Films

• DOI: 10.1021/acsami.3c12342
• Publication Date: 2023-11-08T21:21:53Z
• Authors: Amit Chanda; Deepika Rani; Derick DeTellem; Noha Alzahrani; Dario A. Arena; Sarath Witanachchi; Ratnamala Chatterjee; Manh-Huong Phan; Hariharan Srikanth
• Keywords: Nernst effect; Magnon; Weyl semimetal; Overlayer

Recently, Heusler alloy-based spin gapless semiconductors (SGSs) with high Curie temperature (TC) and sizable polarization have emerged as potential candidates for tunable spintronic applications. We report comprehensive investigation of the temperature-dependent ANE intrinsic longitudinal Seebeck effect (LSSE) in CoFeCrGa thin films grown on MgO substrates. Our findings show that anomalous Nernst coefficient MgO/CoFeCrGa (95 nm) film is ≈1.86 μV K-1 at room temperature, which nearly 2 orders magnitude higher than bulk polycrystalline sample (≈0.018 K-1) almost 3 half-metallic ferromagnet La1-xNaxMnO3 (≈0.005 but comparable to magnetic Weyl semimetal Co2MnGa (≈2-3 K-1). Furthermore, LSSE our nm)/Pt (5 heterostructure ≈20.5 nV Ω-1 twice larger ferromagnetic La0.7Sr0.3MnO3 (≈9 Ω-1). both coefficients follow identical dependences exhibit a maximum ≈225 K, understood combined effects inelastic magnon scatterings reduced population low temperatures. analyses not only indicate extrinsic skew scattering dominating mechanism these also provide critical insights into functional form observed by employing radio frequency transverse susceptibility broad-band resonance combination measurements, we establish correlation among signal, anisotropy, Gilbert damping films, will be beneficial fabricating highly efficient caloritronic nanodevices.