Enhancement of ferromagnetism in Ni-implanted HfO2 dielectric thin films

✍ Scribed by M.K. Sharma; Aloke Kanjilal; Matthias Voelskow; D. Kanjilal; Ratnamala Chatterjee

• Book ID: 103863931
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 680 KB
• Volume: 268
• Category: Article
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2010.03.005

✦ Synopsis

We report thermal annealing and 100 MeV Si 8+ swift heavy ion irradiation effects on the structural and magnetic properties of Ni-implanted HfO 2 thin films. At low Ni doping concentration ($1%), HfO 2 thin films show ferromagnetic behavior. We clearly demonstrate the cluster free nature of our film using cross-sectional high resolution transmission microscopy and magnetization vs. temperature data. Rutherford backscattering spectrometry is used to estimate the film thickness and to establish that Ni-ions are placed in the HfO 2 matrix. By comparing the results for the annealed and swift heavy ion irradiated samples, it is concluded that the enhancement in magnetic signal is closely related to the dispersion/diffusion of implanted Ni and defect creation such as oxygen vacancies. The results of magnetic force microscopy supported the observation of room temperature ferromagnetism in Ni-implanted HfO 2 films.