Tunneling magnetoresistance in epitaxial discontinuous Fe/MgO multilayers

• DOI: 10.1063/1.3569149
• Publication Date: 2011-03-21T22:51:51Z
• Authors: A. García-García; J. A. Pardo; P. Štrichovanec; C. Magén; A. Vovk; J. M. De Teresa; G. N. Kakazei; Y. G. Pogorelov; L. Morellón; P. A. Algarabel; M. R. Ibarra
• Keywords: 02 engineering and technology; 0210 nano-technology

Epitaxial discontinuous Fe/MgO multilayers have been grown by pulsed laser deposition on MgO(001) single-crystal substrates. The multilayers with 0.6 nm nominal Fe layers thickness are superparamagnetic and demonstrate tunneling magnetoresistance (TMR) in the current-in-plane configuration. Increasing deposition temperature causes an improvement in crystal quality and is accompanied by higher TMR ratios. The maximum value (9.2% TMR at room temperature and 18 kOe magnetic field) trebles that of polycrystalline samples deposited simultaneously on glass substrates. A model formula for TMR ratio that includes both spin-dependent tunneling and spin-filtering effect is proposed to explain these results.