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Thermal enhancement of the antiferromagnetic exchange coupling between Fe epilayers separated by a crystalline ZnSe spacer

J. Varalda·J. Milano·A. J. A. de Oliveira·E. M. Kakuno·I. Mazzaro·D. H. Mosca·L. B. Steren·M. Eddrief·M. Marangolo·D. Demaille·V. H. Etgens
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Abstract

We have put into evidence the existence of an antiferromagnetic coupling between iron epilayers separated by a ZnSe crystalline semiconductor. The effect has been observed for ZnSe spacers thinner than 4 nm at room-temperature. The coupling constant increases linearly with temperature with a constant slope of ~5.5x 10-9 J/m2K. The mechanisms that may explain such exchange interaction are discussed in the manuscript. It results that thermally-induced effective exchange coupling mediated by spin-dependent on and off resonant tunnelling of electrons via localized mid-gap defect states in the ZnSe spacer layer appears to be the most plausible mechanism to induce the antiferromagnetic coupling.

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J. Varalda, J. Milano, A. J. A. de Oliveira, E. M. Kakuno, I. Mazzaro, D. H. Mosca, L. B. Steren, M. Eddrief, M. Marangolo, D. Demaille, V. H. Etgens. 2005-03-07. Thermal enhancement of the antiferromagnetic exchange coupling between Fe epilayers separated by a crystalline ZnSe spacer. https://doi.org/10.1088/0953-8984%2F18%2F39%2F036

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