  Epitaxial Y3Fe5O12 thin films have been deposited by off-axis sputtering,
which 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 mV and -5.26
mV in 5-mm long Pt/Y3Fe5O12 and W/Y3Fe5O12 bilayers, respectively, excited by a
radio-frequency magnetic field of 0.3 Oe. From the ferromagnetic resonance
linewidth broadening, the interfacial spin mixing conductance of 4.56E14
{\Omega}-1m-2 and 2.30E14 {\Omega}-1m-2 are obtained for Pt/Y3Fe5O12 and
W/Y3Fe5O12 bilayers, respectively.
