Magnetic field induced order-order phase transition in magnetocaloric systems Mn2−xFexAs0.5P0.5 and MnFeAsyP1−y

► Analysis of differences in formation of magnetic states in Mn2−xFexAsyP1−y was done. ► Based on the results of ab initio calculations and model approach. ► In the Mn2−xFexAs0.5P0.5 system a canted structure in 0.6≤x<0.8 area was found.