“…To investigate the proximity-induced ferromagnetism, X-ray magnetic circular dichroism (XMCD) [40][41][42] and X-ray resonant magnetic reflectivity (XRMR) [43] techniques have been frequently used. Since the end of 1990s, a number of XMCD and XRMR studies focusing on Pt/3d-ferromagnetic-metal (Fe, Ni, Co, and Ni 81 Fe 19 ) junction systems have been reported and the Pt ferromagnetism in these systems has been established [44][45][46][47][48][49][50][51][52][53][54][55][56]. Recently, these techniques were applied for the Pt/magnetic-oxide systems: Pt/Y 3 Fe 5 O 12 [29][30][31]36], Pt/NiFe 2 O 4 [32,33,37], Pt/CoFe 2 O 4 [34,35,37], Pt/MnFe 2 O 4 [37], and Pt/Fe 3 O 4 [37]; in contrast to the Pt/3d-ferromagnetic-metal systems, the proximity-induced Pt ferromagnetism in these Pt/magnetic-oxide systems was found to be undetectably small when the effect of Pt oxidization is negligible [30,31].…”