Proceedings Article | 19 September 2017
KEYWORDS: Magnetism, Oxides, Thin films, N-type semiconductors, Interfaces, Magnetic sensors, Magnetic semiconductors, Semiconductors, Oxygen, Solids
Since the first observation of tunnelling effect in La0.7Sr0.3MnO3 based magnetic structures, the search for high TMR values has been the main goal of research in this field, aiming at developing high sensitive magnetic sensors. Nevertheless, oxides TMR often have high level of noise when using SrTiO3 as insulating barrier drastically reducing the interest of such devices [1]. Recently we introduced the use of heavily doped n-type semiconductor SrTi0.8Nb0.2O3 as fully depleted layer to form the insulating barrier [2-3]. Magneto-transport properties of the MTJs were studied as a function of applied bias, temperature and barrier thickness. It is found that using semiconducting barrier at the place of the standard insulator, leads to a significantly improved reproducibility of results and in the spectral noise density reduced by three orders of magnitude at low temperature. We ascribe that fact to a strongly reduced amount of defects, such as oxygen vacancies, in doped SrTi0.8Nb0.2O3. This results brings novel opportunities to develop high sensitive magnetic devices working at low temperature.
[1] A. Solignac, G. Kurij, R. Guerrero, G. Agnus, T. Maroutian, C. Fermon, M. PArnnetier-Lecoeur, Ph. Lecoeur, SPIE Proceedings Series, 2015, 9551, pp.95512F (2016)
[2] G. Kurij, A. Solignac, T. Maroutian, G. Agnus, R. Guerrero, L. E. Calvet, M. Pannetier-Lecoeur, and Ph. Lecoeur, Appl. Phys. Lett. 110, 082405 (2017)
[3] G. Kurij, L. E. Calvet, R. Guerrero, T. Maroutian, G. Agnus, A. Solignac, and Ph. Lecoeur, Thin Solid Films vol. 716, part B, 82-85 (2016)
