Magnetic Proximity Effect In Magnetic-Insulator/Heavy-Metal Heterostructures Across The Compensation Temperature

The magnetic proximity effect in Pt and W thin films grown on Dy3Fe5O12 (DyIG) is examined at temperatures above and below the magnetic compensation temperature of the ferrimagnetic insulator. Polarized neutron reflectometry indicates that the proximity effect is positive in Pt/DyIG both above and below the compensation temperature, and x-ray magnetic circular dichroism shows a weak positive W magnetization below compensation in W/DyIG. This demonstrates a qualitative difference compared to heavy metal/ferrimagnetic rare earth-transition metal alloys, where the proximity-induced magnetism of the heavy metal changes sign at the compensation temperature. Reflectometry, structural, and spin transport measurements show that depositing the heavy metal film on the ferrimagnetic insulator in situ without breaking vacuum avoids the formation of a low density interfacial layer between the Pt and DyIG.