Spin filtering effect in intrinsic 2D magnetic semiconductor Cr₂Ge₂Te₆

All van der Waals Fe 3 GeTe 2 /Cr Ge Te 6 /graphite magnetic heterojunctions have been fabricated via mechanical exfoliation and stacking, their magnetotransport properties are studied in detail. At low bias voltages, large negative junction magnetoresistances observed attributed to spin-conserving tunneling transport across an insulating Cr layer. With increasing bias, a crossover Fowler–Nordheim takes place. The sign of the magnetoresistance suggests that bottom conduction band belongs minority spins, opposite findings some first-principles calculations. This work shows vdW heterostructures based on 2D insulators valuable platform gain further insight into spin polarized transport, which is basis for pursuing high performance spintronic devices variety quantum phenomena.