  Exchange-coupled interfaces are pivotal in exploiting two-dimensional (2D)
ferromagnetism. Due to the extraordinary correlations among charge, spin,
orbital and lattice degrees of freedom, layered magnetic transition metal
chalcogenides (TMCs) bode well for exotic topological phenomena. Here we report
the realization of wafer-scale Cr2Te3 down to monolayer (ML) on insulating
SrTiO3(111) and/or Al2O3(001) substrates using molecular beam epitaxy. Robust
ferromagnetism persists in the 2D limit. In particular, the Curie temperature
TC of 2 ML Cr2Te3 increases from 100 K to ~ 120 K when proximitized to
topological insulator (TI) (Bi,Sb)2Te3, with substantially boosted
magnetization as observed via polarized neutron reflectometry. Our experiments
and theory strongly indicate that the Bloembergen-Rowland interaction is likely
universal underlying TC enhancement in TI-coupled magnetic heterostructures.
The topological-surface-enhanced magnetism in 2D TMC enables further exchange
coupling physics and quantu
