X-ray powder diffraction investigation of the crystal structure of LaFe12(B,C)6 and R(Co,Ni)12B6 series of compounds

RM12B6 phases (M=Fe,Co,Ni R=4f ones) are exhibiting interesting itinerant-electron (IE) magnetic behavior. We are particularly interested in the evolution of the crystal structure, the unit cell parameters, volume and crystal symmetry depending upon the composition. We also aim to investigate the influence of the nature of the C for B substitution on the crystal lattice. ie: LaFe12(B,C)6 is a remarkable IE metamagnetic system with a large interplay between physical properties and volume. The profound bonding, structural, electronic, and magnetic changes, which occur in this system, lead to rich variety of unusually powerful magneto-responsive properties, such as giant magnetocaloric effect, colossal magnetostriction, giant magnetoresistance, and huge magnetovolume effects. Such a large variety of different functional properties makes this material family outstanding. We want to determine the evolution of the crystal structure, the variation of the unit cell and symmetry by powderXRD