Veranstaltungsdetails

1.7.2014, 17:00
Jungiusstr. 11, Hörsaal AP

SFB 668 - Kolloquium

Dr. Ph. Sainctavit (SLS and Soleil, France):

Magnetic memory of a single-molecule quantum magnet wired to a gold surface

In the field of molecular spintronics the use of magnetic molecules for information technology is a main target and the observation of magnetic hysteresis on individual molecules organized on surfaces is a necessary step to develop molecular memory arrays. Information storage at the molecular level requires molecules exhibiting an intrinsic remnant magnetization, like the so-called single-molecule magnets[1] (SMMs). These have been intensively investigated for their rich quantum behaviour[2] but no magnetic hysteresis had been so far reported for monolayers of SMMs on various non-magnetic substrates, most probably owing to the chemical instability of clusters on surfaces[3]. Using X-ray absorption spectroscopy and X-ray magnetic circular dichroism synchrotron-based techniques, pushed to the limits in sensitivity and operated at sub-kelvin temperatures (400 mK), we have now found that robust, tailor-made Fe4 complexes retain magnetic hysteresis at gold surfaces [4,5,6]. Our results demonstrate that isolated SMMs can be used for storing information. The road is now open to address individual molecules wired to a conducting surface in their blocked magnetization state, thereby enabling investigation of the elementary interactions between electron transport and magnetism degrees of freedom at the molecular scale. [1] R. Sessoli et al. Nature 365, 141?143 (1993). [2] D. Gatteschi et al. Molecular Nanomagnets (Oxford Univ. Press, 2006). [3] M. Mannini, Ph. Sainctavit et al. Chemistry : a European Journal 14, 7530?7535 (2008). [4] M. Mannini, F. Pineider, Ph. Sainctavit et al. Nature Materials 8, 194?197 (2009). [5] M. Mannini, F. Pineider, Ph. Sainctavit et al. Advanced Materials 21, 167?171 (2009). [6] M. Mannini, F. Pineider, Ph. Sainctavit et al. Nature 468, 417?421 (2010).