Large spin pumping from epitaxial Y3Fe5O12 thin films to Pt and W layers

Epitaxial Y3Fe5O12 thin films deposited by off-axis sputtering exhibit excellent crystalline quality enabling observation of large spin pumping signals in Pt/Y3Fe5O12 and W/Y3Fe5O12 bilayers driven by cavity ferromagnetic resonance. The inverse spin Hall voltages reach 2.10 and -5.26 mV in 5-mmlong Pt/Y3Fe5O12 and W/Y3Fe5O12 bilayers, respectively, excited by a radio-frequency magnetic field of 0.3 Oe. From the ferromagnetic resonance linewidth broadening, we obtain high interfacial spin mixing conductances of 4.56 x 10(14) and 2.30 x 10(14) Omega(-1) m(-2) for Pt/Y3Fe5O12 and W/Y3Fe5O12 bilayers, respectively.