  The spin-orbit torques (SOTs) generated from topological insulators (TIs)
have gained increasing attention in recent years. These TIs, which are
typically formed by epitaxially grown chalcogenides, possess extremely high SOT
efficiencies and have great potential to be employed in the next-generation
spintronics devices. However, epitaxy of these chalcogenides is required to
ensure the existence of topologically-protected surface state (TSS), which
limits the feasibility of using these materials in industry. In this work, we
show that non-epitaxial Bi$_{x}$Te$_{1-x}$/ferromagnet heterostructures
prepared by conventional magnetron sputtering possess giant SOT efficiencies
even without TSS. Through harmonic voltage measurement and hysteresis loop
shift measurement, we find that the damping-like SOT efficiencies originated
from the bulk spin-orbit interactions of such non-epitaxial heterostructures
can reach values greater than 100% at room temperature. We further demonstrate
current-induced SOT switching in these Bi$_{x}$Te$_{1-x}$-based
heterostructures with thermally stable ferromagnetic layers, which indicates
that such non-epitaxial chalcogenide materials can be potential efficient SOT
sources in future SOT magnetic memory devices.
