Defect-induced ferromagnetism in undoped and Mn-doped zirconia thin films

Phys. Rev. B 82, 125209 (2010)

Jan Zippel, Michael Lorenz, Annette Setzer, Gerald Wagner, Nikolai Sobolev, Pablo Esquinazi, and Marius Grundmann 


A doping-independent ferromagnetic hysteresis at 300 and 5 K was found for both undoped and Mn-doped zirconia thin films with up to 20 at. % Mn. The lack of Mn-induced magnetic ordering is a strong indication that the observed ferromagnetic effects are defect related. Electron paramagnetic resonance analysis supports the conclusion that Mn ions are in a magnetically “silent” state. Cubic ZrO2:Mn films show a noticeable layer ferromagnetic saturation magnetization at 5 K, as compared to the monoclinic and tetragonal films, which clearly correlates with strain and a higher density of dislocations as the dominating microstructural defect.