  The field of oxide spintronics can strongly benefit from the establishment of
robust ferromagnetic insulators with near room-temperature Curie temperature.
Here we investigate the structural, electronic, and magnetic properties of
atomically-precise epitaxially-strained thin films of the double perovskite
La$_2$NiMnO$_6$ (LNMO) grown by off-axis radio-frequency magnetron sputtering.
We find that the films retain both a strong insulating behavior and a bulk-like
Curie temperature in the order of 280 K, nearly independently from epitaxial
strain conditions. These results suggest a prospective implementation of LNMO
films in multi-layer device architectures where a high-temperature
ferromagnetic insulating state is a prerequisite.
