A study of the structural and magnetic properties of ZnO implanted by Gd ions

作者：Mackova A^*; Malinsky P; Sofer Z; Simek P; Sedmidubsky D; Mikulics M; Wilhelm R A

来源：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , 2014, 332: 80-84.

DOI：10.1016/j.nimb.2014.02.034

• ZnO
• Gd implantation
• Depth profiles
• RBS channelling
• Raman spectroscopy
• AFM

The structural and magnetic properties of ZnO (0001) single crystals implanted with 200 keV Gd ions up to a fluence of 5 x 1015 cm(-2) and subsequently annealed at 800 degrees C in various atmospheres were studied. The chemical composition and concentration depth profiles of ion-implanted layers were characterised by Rutherford Back-Scattering spectrometry (RBS) and compared to SRIM simulations. The as-implanted Gd depth profiles were found to be broader than those simulated by SRIM, but the projected range coincided well with that simulated. After annealing at 800 degrees C, the depth profiles became narrower. The structural changes in the layers modified by ion implantation and subsequent annealing were characterised by RBS channelling. The annealing led to partial recrystallisation and a decrease in the number of Gd atoms situated in substitutional positions. Raman spectroscopy showed that the point defects in Zn and O vacancies had been created by implantation and that these defects are most effectively cured after annealing in oxygen atmosphere. AFM analysis was used to determine the surface-morphology changes after the implantation and annealing procedures. The as-implanted samples exhibited ferromagnetism persisting up to room temperature. The annealing procedure led to paramagnetic behaviour, probably caused by the formation of gadolinium clusters.

• 出版日期2014-8-1