Room temperature ferromagnetism in monoclinic Mn-doped ZrO 2 thin films

• Published in: Journal of applied physics 2012-04, Vol.111 (7), p.07C302-07C302-3
• Main Authors: Hoa Hong, Nguyen, Park, C.-K., Raghavender, A. T., Ciftja, O., Bingham, N. S., Phan, M. H., Srikanth, H.
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.3670577

Theory has predicted that high temperature ferromagnetism (FM) should be found in cubic Mn-doped ZrO 2 . Our experimental data reveal room temperature FM in Mn-doped ZrO 2 thin films grown on LaAlO 3 substrates. The largest saturated magnetic moment ( M s ) is found to be about 13.8 μ B /Mn for the cubic Mn 0.05 Zr 0.95 O 2 films and it decreases as the Mn content increases. In this case, the intrinsic FM is strongly associated with the cubic structure of Mn-doped ZrO 2 , and the Mn-Mn exchange interactions via intermediate oxygen atoms is important. Room temperature FM is also observed in monoclinic Mn-doped ZrO 2 thin films grown on Yttrium Stabilized Zirconia (YSZ) substrates, however, with a completely different nature. Though pristine monoclinic ZrO 2 films are already ferromagnetic, doping Mn can enhance the magnetic moment by about 40% ( M s is 2.68 μ B /Mn). Differently from the cubic case, FM in monoclinic Mn-doped ZrO 2 films does not come only via exchange interactions, but also from defects.