  Tuning magnetic properties of magnetic topological materials is of interest
to realize elusive physical phenomena such as quantum anomalous hall effect
(QAHE) at higher temperatures and design topological spintronic devices.
However, current topological materials exhibit Curie temperature (TC) values
far below room temperature. In recent years, significant progress has been made
to control and optimize TC, particularly through defect engineering of these
structures. Most recently we showed evidence of TC values up to 80K for
(MnSb2Te4)x(Sb2Te3)1-x, where x is greater than or equal to 0.7 and less than
or equal to 0.85, by controlling the compositions and Mn content in these
structures. Here we show further enhancement of the TC, as high as 100K, by
maintaining high Mn content and reducing the growth rate from 0.9 nm/min to 0.5
nm/min. Derivative curves reveal the presence of two TC components contributing
to the overall value and propose TC1 and TC2 have distinct origins: excess Mn
in SLs and Mn in Sb2-yMnyTe3QLs alloys, respectively. In pursuit of elucidating
the mechanisms promoting higher Curie temperature values in this system, we
show evidence of structural disorder where Mn is occupying not only Sb sites
but also Te sites, providing evidence of significant excess Mn and a new
crystal structure:(Mn1+ySb2-yTe4)x(Sb2-yMnyTe3)1-x. Our work shows progress in
understanding how to control magnetic defects to enhance desired magnetic
properties and the mechanism promoting these high TC in magnetic topological
materials such as (Mn1+ySb2-yTe4)x(Sb2-yMnyTe3)1-x.
