  We investigate the spin-current transport through antiferromagnetic insulator
(AFMI) by means of the spin-Hall magnetoressitance (SMR) over a wide
temperature range in Pt/NiO/Y$_3$Fe$_5$O$_{12}$ (Pt/NiO/YIG) heterostructures.
By inserting the AFMI NiO layer, the SMR dramatically decreases by decreasing
the temperature down to the antiferromagnetically ordered state of NiO, which
implies that the AFM order prevents rather than promotes the spin-current
transport. On the other hand, the magnetic proximity effect (MPE) on induced Pt
moments by YIG, which entangles with the spin-Hall effect (SHE) in Pt, can be
efficiently screened, and pure SMR can be derived by insertion of NiO. The dual
roles of the NiO insertion including efficiently blocking the MPE and
transporting the spin current from Pt to YIG are outstanding compared with
other antiferromagnetic (AFM) metal or nonmagnetic metal (NM).
