Ferromagnetic resonance of perpendicularly magnetized Tm3Fe5O12/Pt heterostructures

• Published in: Applied physics letters 2019-10, Vol.115 (17)
• Main Authors: Crossley, S., Quindeau, A., Swartz, A. G., Rosenberg, E. R., Beran, L., Avci, C. O., Hikita, Y., Ross, C. A., Hwang, H. Y.
• Format: Article
• Language: English
• Subjects: Applied physics; Bilayers; Broadband; Damping; Ferrimagnetism; Ferromagnetic resonance; Ferromagnetism; Gadolinium-gallium garnet; Heterostructures; Magnetic anisotropy; MATERIALS SCIENCE; Resistance; Spin dynamics; Spin-orbit interactions; Spintronics; Substrates; Thin films
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5124120

Broadband ferromagnetic resonance is used to investigate magnetization dynamics, damping, interfacial spin transport, and perpendicular magnetic anisotropy (PMA) of (111)-oriented epitaxial thin films of the ferrimagnetic insulator Tm3Fe5O12 (TmIG) on substrates of (111)-oriented Gd3Ga5O12. A PMA field of ∼162 mT is found at 350 K, in the temperature range where spin–orbit torque switching was previously reported [Avci et al., Nat. Mater. 16, 309–314 (2017)]. A Landé g-factor of 1.56 strongly supports large intrinsic spin–orbit coupling due to the presence of the heavy rare earth Tm. Gilbert damping coefficients α are compared for three samples: a 28 nm thin TmIG film (α ∼ 0.014), a TmIG (28 nm)/Pt (6 nm) bilayer (α ∼ 0.022), and a TmIG (28 nm)/Cu (3 nm)/Pt (6 nm) trilayer (α ∼ 0.024). Applying the spin pumping formalism, we find that the real part of the effective interfacial spin mixing conductance Geff↑↓ = 5.7 × 1014 Ω−1 m−2 is comparable to that of well-studied garnet/Pt interfaces. Our work strengthens the candidacy of TmIG for spintronics applications requiring PMA in insulating thin films.