Scaling of the thermally induced sign inversion of longitudinal spin Seebeck effect in a compensated ferrimagnet: Role of magnetic anisotropy

Abstract

We report on a systematic investigation of the longitudinal spin Seebeck effect (LSSE) in a GGG(Gd3Ga5O12)/GdIG(Gd3Fe5O12)/Pt film series exhibiting an in-plane magnetic easy axis with a compensation temperature (T_Comp) that decreases from 270 to 220 K when decreasing GdIG film thickness from 272 to 31 nm, respectively. For all the films, the LSSE signal flips its sign below T_Comp. We demonstrate a universal scaling behavior of the temperature dependence of LSSE signal for our GdIG films around their respective T_Comp. Additionally, we demonstrate LSSE in a 31 nm GdIG film grown on a lattice-mismatched GSGG (Gd3Sc2Ga3O12) substrate that exhibits an out-of-plane magnetic easy axis at room temperature. However, this sample reveals a spin reorientation transition where the magnetic easy axis changes its orientation to in-plane at low temperatures. We observed a clear distinction in the LSSE signal for the GSGG/GdIG(31 nm)/Pt heterostructure, relative to GGG/GdIG(31nm)/Pt showing an in-plane magnetic easy axis. Our findings underscore a strong correlation between the LSSE signal and the orientation of magnetic easy axis in compensated ferrimagnets and opens the possibility to tune LSSE through effective anisotropy.

Accepted in Advanced Functional Materials

References in corpus (7)

• Spin Seebeck insulator
• Theory of magnon-driven spin Seebeck effect
• Magnon Mediated Electric Current Drag Across a Ferromagnetic Insulator Layer
• Spin convertance at magnetic interfaces
• Spin Seebeck effect in antiferromagnets and compensated ferrimagnets
• Critical behavior and magnetocaloric effect across the magnetic transition in Mn${}_{1+x}$Fe${}_{4-x}$Si${}_3$
• X-ray interference effects on the determination of structural data in ultrathin La2/3Sr1/3MnO3 epitaxial thin films