Magnetic properties and thermal stability of N-doped CrO 2 (100) films

Abstract Chromium dioxide (CrO 2 ) is one of the perfect candidates for application in the field of spintronics due to its 100% spin polarization around the Fermi surface. In this work, N-doped epitaxial CrO 2 (100) films were successfully synthesized on TiO 2 substrates using the chemical vapor deposition technique in the nitrogen-involved atmosphere. The deposition window of N-doped CrO 2 ranged from 300 to 430°C in contrast to narrow temperature window for CrO 2 in pure O 2 atmosphere. Compared with pure CrO 2 , N-doped films have better film quality, narrower orientation distribution and lower roughness. It was also found that the magnetic anisotropy and Curie temperature of the CrO 2 film increased respectively with the N concentration, suggesting that N-doping offer an efficiently way for anisotropy manipulation. The annealing tests further reveal improved thermal stability of the N-doped film, N-doped films can withstand annealing temperatures as high as 470 °C in contrast to 420 °C for pure CrO 2 . The investigation on the electronic structure of N-doped CrO 2 via first principle calculations suggests that N-doping only slightly affects the density of states of CrO 2 without changing its half metallicity. Based on these results, N-doped CrO 2 films may be promising for applications in spintronic devices.