  Great efforts have been made to the investigation of defects in silicon
carbide for their attractive optical and spin properties. However, most of the
researches are implemented at low and room temperature. Little is known about
the spin coherent property at high temperature. Here, we experimentally
demonstrate coherent control of divacancy defect spins in silicon carbide above
550 K. The spin properties of defects ranging from room temperature to 600 K
are investigated, in which the zero-field-splitting is found to have a
polynomial temperature dependence and the spin coherence time decreases as the
temperature increases. Moreover, as an example of application, we demonstrate a
thermal sensing using the Ramsey method at about 450 K. Our experimental
results would be useful for the investigation of high temperature properties of
defect spins and silicon carbide-based broad-temperature range quantum sensing.
