Nature of weak magnetism in SrTiO&lt;sub&gt;3&lt;/sub&gt;/LaAlO&lt;sub&gt;3&lt;/sub&gt; multilayers

Salman, Z.; Ofer, O.; Radovic, M.; Hao, H.; Ben Shalom, M.; Chow, K.H.; Dagan, Y.; Hossain, M.D.; Levy, C.D.P.; MacFarlane, W.A.; Morris, G.M.; Patthey, L.; Pearson, M.R.; Saadaoui, H.; Schmitt, T.; Wang, D.; Kiefl, R.F.

doi:10.1103/PhysRevLett.109.257207

Nature of weak magnetism in SrTiO₃/LaAlO₃ multilayers

Salman Z, Ofer O, Radovic M, Hao H, Ben Shalom M, Chow KH, Dagan Y, Hossain MD, Levy CDP, MacFarlane WA, Morris GM, Patthey L, Pearson MR, Saadaoui H, Schmitt T, Wang D & Kiefl RF

Citation

Salman, Z., Ofer, O., Radovic, M., Hao, H., Ben Shalom, M., Chow, K. H., … Kiefl, R. F. (2012). Nature of weak magnetism in SrTiO₃/LaAlO₃ multilayers. Physical Review Letters, 109(25), 257207 (5 pp.). https://doi.org/10.1103/PhysRevLett.109.257207

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:12871

We report the observation of weak magnetism in superlattices of LaAlO₃/SrTiO₃ using β-detected nuclear magnetic resonance. The spin lattice relaxation rate of ⁸Li in superlattices with a spacer layers of 8 and 6 unit cells of LaAlO₃ exhibits a strong peak near ∼35 K, whereas no such peak is observed in a superlattice with spacer layer thickness of 3 unit cells. We attribute the observed temperature dependence to slowing down of weakly coupled electronic moments at the LaAlO₃/SrTiO₃ interface. These results show that the magnetism at the interface depends strongly on the thickness of the spacer layer, and that a minimal thickness of ∼4-6 unit cells is required for the appearance of magnetism. A simple model is used to determine that the observed relaxation is due to small fluctuating moments (∼0.002μ_B) in the two samples with a larger LaAlO₃ spacer thickness.