Press release

The future of ram memories goes nano

28/07/2017

Critical thickness determination in different spintronics materials, manganese oxides (red) and Gallium arsenide (green)
Critical thickness determination in different spintronics materials, manganese oxides (red) and Gallium arsenide (green)

An international research team, coordinated by Istituto officina dei materiali Trieste, and in collaboration with two Cnr institutes,  Istituto per lo studio dei materiali nanostrutturati (Bologna) and Spin institute (Napoli) has been able to quantify at a nanometer level (nanometer, a distance corresponding to 1 billionth of a meter) the ‘critical thickness’ of some relevant spintronics material (spintornics=spin transport electronics).
This research field is a new and emergent field in electronics: spintronics devices are based on the control of the spin, a purely quantum property of the electrons corresponding to the fundamental magnetic information. Electron spin could be ‘up’ or ‘down’; such binary condition makes electron spin  a very good candidate at encoding information, in strict analogy with the 0 and 1 values of binary code.
“Thanks to the use of Synchrotron Radiation, a special light that allows the study of materials with nanometers sensitivity, we have been able to evaluate the ‘critical thickness’ is between 3 and 4 nanometer fromt the surface, a new result giving useful information to researchers willing to build new technology and devices based on new materials as manganites, explains Giancarlo Panaccione, researcher at Cnr. As critical thickness we intend the value of thickness at which both the magnetic and the electronic behavior of the two studied materials (the magnetic manganese oxides LSMO and the diluted magnetic semiconductor (Ga,Mn)As) start to change with respect to the surface. “Being able to quantify this distante is a fundamental information to the control of the magnetization and of the potential speed of data storage, parameters strongly dependent on both the structural and electronic properties”, says Panaccione. “In fact, we show that fully bulk properties are restored in the oxide at a deeper thickness (depth with respect to the surface) compared to the semiconductor”. Electronics has been so far based on the control of the charge carriers (the electrons) without exploiting the spin properties. In 1988, the discovery of ‘Giant magnetoresistance’, i.e. the birth of spintronic research, that a few years later, in 2007, gave the Nobel prize for physics to its inventors, A. Fert e P. Grunberg. “Present and future applications of engineering and designing of spintronic devices point towards new position sensitive devices and digital data storage”, concludes Panaccione. In recent years, research in nanotechnology and nanometer sized materials revealed to be essential to satisfy the request of commercial devices smaller and faster. 

What: https://www.nature.com/articles/ncomms16051, ‘Quantifying the critical thickness of electron hybridization in spintronics materials’, T. Pincelli, V. Lollobrigida, F. Borgatti, A. Regoutz, B. Gobaut, C. Schlueter, T. -L. Lee, D. J. Payne, M. Oura, K. Tamasaku, A. Y. Petrov, P. Graziosi, F. Miletto Granozio, M. Cavallini, G. Vinai, R. Ciprian, C. H. Back, G. Rossi, M. Taguchi, H. Daimon, G. van der Laan.; G. Panaccione

For further information: Giancarolo Panaccione, Iom-Cnr, ph. + 39 040/3758409 / 8075, e-mail:  panaccione@iom.cnr.it;
Francesco Borgatti, Ismn-Cnr,  ph. + 39 051/638.8518, e-mail: borgatti@bo.ismn.cnr.it;
Elio Nello Meucci, Ufficio stampa Cnr,  ph. + 3906/49932079, e-mail: elionello.meucci@amministazione.cnr.it 

Head of Press Office Cnr: Marco Ferrazzoli,  ph. + 39 06/49933383,  e-mail marco.ferrazzoli@cnr.it, skype marco.ferrazzoli1