Structural and magnetic properties in Mn-doped ZnO films prepared by pulsed-laser deposition

•We observed only low temperature ferromagnetism (LTFM) in Mn-doped ZnO films with the doping concentration of 5at%.•Positron annihilation spectroscopy indicates that the zinc vacancies cannot act as the origin of the LTFM in those films.•The mechanism of VO-mediated FM is not confirmed in our experiments.•It is confirmed by experiments that the LTFM in those films can be interpreted as p–d hybridization from indirect coupling of substitutional Mn2+ ions. We investigated the structural and magnetic properties of Zn0.95Mn0.05O films prepared on sapphire substrates by pulsed-laser deposition. Only low temperature ferromagnetism (Curie temperature lower than 50K) was observed in Mn-doped samples, while pure ZnO film shows a typical paramagnetic behavior. Structural analyses indicate that the substitutional Mn2+ ions play a significant role for the low temperature ferromagnetism. Lattice defects such as VO and VZn were not proven to be effective factors for the origin of ferromagnetism in the films. The low temperature ferromagnetism might be interpreted as p–d hybridization from indirect coupling of Mn ions (Mn–O–Mn).