First-principles calculations are used to investigate the magnetic properties
of Ti1−x​Crx​N solid solutions. We show that the magnetic interactions
between Cr spins that favour antiferromagnetism in CrN is changed upon alloying
with TiN leading to the appearance of ferromagnetism in the system at
approximately x≤0.50 in agreement with experimental reports. Furthermore
we suggest that this effect originates in an electron density redistribution
from Ti to Cr that decreases the polarization of Cr d-states with t2g​
symmetry while it increases the polarization of Cr d-states with eg​
symmetry, both changes working in favour of ferromagnetism.Comment: 21 pages, 7 figure