Local zincblende coordination in heteroepitaxial wurtzite Zn1−xMgxO:Mn thin films with 0.01 ≤ x ≤ 0.04 identified by electron paramagnetic resonance. Issue 45 (2nd November 2015)

• Record Type: Journal Article
• Authors: Böttcher, Rolf; Lorenz, Michael; Pöppl, Andreas; Spemann, Daniel; Grundmann, Marius
• Is Part Of: Journal of materials chemistry. Volume 3:Issue 45(2015)
• Page Start: 11918
• Page End: 11929
• Publication Date: 2015-11-02
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c5tc02720a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Heteroepitaxial Zn1− x Mg x O:Mn thin films show already at x = 0.01 a local cubic zincblende coordination attributed to stacking faults. Abstract : Zn1− x Mg x O:Mn thin films with atomic Mg content x below about 0.3 are well known to crystallize in the hexagonal wurtzite structure. Here we demonstrate that beginning with a chemical Mg content of already x = 0.01 in heteroepitaxial Zn1− x Mg x O:Mn thin films, a local cubic zincblende coordination of the Mn ion can be identified using electron paramagnetic resonance of Mn 2+ ions. The appearance of a cubic Mn 2+ spectrum in the wurtzite (Zn, Mg)O films is attributed to an enhanced formation of stacking faults providing zincblende structure locally. The Mn 2+ ions are incorporated at zinc lattice sites into the Zn1− x Mg x O films and their zero field spitting allows to monitor even small structural changes in the MnO4 tetrahedrons. Alloying with the smaller Mg 2+ ions leads to a shrinking of the Mn–O bond length in dependence on the axial distortion of the parent ZnO4 . Our findings generally show that Mn 2+ ions in low concentration represent a highly sensitive paramagnetic probe in group II–VI thin films.