The structure, electrical and magnetic properties of M-doped PbPdO_2 (M = Cu, Co, Fe) thin films: A first-principles and experimental study

摘要

PbPdO2 and M-doped PbPdO2 (M = Cu, Co, Fe) films were prepared using pulsed laser deposition (PLD) method. The structures, electrical and magnetic properties were systematically investigated by XRD, Raman, SEM, XPS, AFM and VSM. Our results indicate that PbPdO2 and PbPd0.9M0.1O2 (M = Cu, Co, Fe) film with (0 0 2) preferred orientation can be well fabricated. The valence states of magnetic atoms in M-doped PbPdO2 (M = Cu, Co, Fe) thin films are identified to be Cu1+, Co-2+,Co-3+ and Fe3+, respectively. All Pb(Pd,M)O-2 (M = Cu, Co, Fe) films exhibit ferromagnetism with high metal-insulator transition temperatures at around 330-370 K. Moreover, the resistivity of Fe doped PbPdO2 film is higher than that of the pristine PbPdO2 film, while the resistivities of Co and Cu doped PbPdO2 films are lower. At the same time, Fe, Co and Cu dopants do enhance the ferromagnetism of PbPdO2 film, while the enhancement of magnetic moment for Fe dopant is most evident. Lastly, based on Pb vacancy and O-1 observed experimentally, the band gaps and magnetic moments of Pb(Pd,M)O-2 films were calculated by first-principles, and the results explain well the experimental facts.