9
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      A Search for Defect Related Ferromagnetism in SrTiO\(_3\)

      Preprint
      , ,

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Room temperature ferromagnetic hysteresis is observed in commercial SrTiO\(_3\) substrates purchased from a variety of suppliers. It is shown that the ferromagnetic signal comes from the unpolished surfaces. Surface impurity phases cannot be detected using either x-ray diffraction or energy dispersive x-ray spectra on the unpolished surfaces. However, a possible correlation between surface disorder (xray diffraction peak linewidth) and ferromagnetism is observed. Ar ion bombardment (10keV-90 keV) can be used to produce surface layer disorder but is not found to induce ferromagnetism. Annealing of the substrates at temperatures ranging from 600 to 1100 \(^\circ\)C is found to alter the hysteresis curves differently depending on whether the annealing is performed in air or in vacuum. Identical annealing behaviour is observed if the substrates are artificially spiked with iron. This suggests that the ferromagnetic hysteresis of as purchased SrTiO\(_3\) could be due to Fe contamination of the unpolished surfaces. In addition, it is shown that no ferromagnetism is observed in samples that contain \(10^{19}-10^{21}\) cm\(^{-3}\) of oxygen vacancies if all the faces are polished.

          Related collections

          Most cited references6

          • Record: found
          • Abstract: not found
          • Article: not found

          Superconducting Transition Temperatures of Semiconducting SrTiO3

            Bookmark
            • Record: found
            • Abstract: found
            • Article: found
            Is Open Access

            Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxides

            Room-temperature ferromagnetism has been observed in the nanoparticles (7 - 30 nm dia) of nonmagnetic oxides such as CeO2, Al2O3, ZnO, In2O3 and SnO2. The saturated magnetic moments in CeO_2 and Al_2O_3 nanoparticles are comparable to those observed in transition metal doped wide band semiconducting oxides. The other oxide nanoparticles show somewhat lower values of magnetization but with a clear hysteretic behavior. Conversely, the bulk samples obtained by sintering the nanoparticles at high temperatures in air or oxygen became diamagnetic. As there were no magnetic impurities present, we assume that the origin of ferromagnetism may be due to the exchange interactions between localized electron spin moments resulting from oxygen vacancies at the surfaces of nanoparticles. We suggest that ferromagnetism may be a universal characteristic of nanopartilces of metal oxides
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Surfaces of reduced and oxidizedSrTiO3from atomic force microscopy

                Bookmark

                Author and article information

                Journal
                02 August 2010
                Article
                10.1063/1.3481344
                1008.0299
                f198eefd-8e39-4317-8801-fccdcdcc4516

                http://arxiv.org/licenses/nonexclusive-distrib/1.0/

                History
                Custom metadata
                20 pages, 7 figures, 3 tables, accepted in Journal of Applied Physics
                cond-mat.mtrl-sci

                Comments

                Comment on this article