Rare earth Ce3+doping regulated the electronic structure and magnetic properties of Ni2P nanoparticles: Experimental and theoretical study

Heteroatom doping is a productive strategy to manipulate the properties of nanomaterials. Herein, we for the first time reported the fabrication of homogeneous cerium doped Ni2P hollow nanoparticles (CexNi1-x)(2)P, (0 <= x <= 0.05) by thermal decomposition, and investigate cerium doping on the electronic structure and magnetic properties through experimental and theoretical studies. Cerium exists as Ce3+ in the (CexNi1-x)(2)P nanoparticles, which maintain intrinsic hexagonal structure and hollow morphology. Ce3+ preferentially occupies the tetrahedral sites of Ni2P lattice, leading to enhanced ferromagnetic properties at room temperature. By increasing the content of Ce3+, the saturation magnetization (M-s) values increase first and then decrease. 1 at% Ce3+ doped Ni2P nanoparticles reaches the highest M-s value of 0.028 emu/g, 7 times larger than undoped Ni2P. First principles calculations show that Ce3+ doping can improve the metallic properties and induce magnetic ordering in paramagnetic Ni2P. The magnetic moment mainly originates from the 4f orbital of Ce3+, and decreases by increasing the doped Ce3+, which is accordant with the experimental phenomena. Ferromagnetic-antiferromagnetic oscillation occurs in Ce3+ doped Ni2P, suggesting that the particular ferromagnetic coupling is ascribed to the RKKY interactions between itinerant electrons in metallic Ni2P host and localized electrons in Ce3+.