Modification of magnetic anisotropy through3d−4fcoupling in La0.75Pr0.25Co2P2

Magnetic behavior of La${}_{0.75}$Pr${}_{0.25}$Co${}_{2}$P${}_{2}$ was investigated by a combination of magnetic measurements, magneto-optical imaging, neutron diffraction, and x-ray absorption spectroscopy, including x-ray magnetic circular dichroism. The material crystallizes in the ThCr${}_{2}$Si${}_{2}$ structure type and exhibits three consecutive magnetic phase transitions. At 167 K, the Co magnetic moments order ferromagnetically in the $ab$ plane of the tetragonal crystal structure. At 66 K, a ferromagnetic ordering of Pr(4$f$) moments parallel to the $c$ axis causes a rotation of the Co(3$d$) moments towards the $c$ axis in the direction opposite to the Pr moments, thus forming a noncollinear ferrimagnetically ordered structure and switching the direction of the total magnetization from the $ab$ plane to the $c$ axis. The third magnetic transition observed at 35 K is likely associated with the establishment of the collinear ferrimagnetic order along the $c$ axis.