Аннотация:Melting of rhombohedral boron subnitride B13N2 has been studied in situ at pressures to 8 GPausing synchrotron Xray diffraction and electrical resistivity measurements. It has been found that above2.6 GPa B13N2 melts incongruently, and the melting curve exhibits positive slope of 31(3) K/GPa thatpoints to a lower density of the melt as compared to the solid phase.