On melting of boron subnitride $B_{13}N_{2}$ under pressure

摘要

Melting of rhombohedral boron subnitride B$_{13}$N$_2$ has been studied in situ at pressures to 8 GPa using synchrotron X-ray diffraction and electrical resistivity measurements. It has been found that above 2.6 GPa B$_{13}$N$_2$ melts incongruently, and the melting curve exhibits positive slope of 31(3) K/GPa that points to a lower density of the melt as compared to the solid phase.