Naslov
High Mobility in LaAlO_3/SrTiO_3 Heterostructures: Origin, Dimensionality and Perspectives

Autori
Herranz, Gervasi ; Basletić, Mario ; Bibes, Manuel ; Maurice, Jean-Luc ; Copie, Olivier ; Carretero, Cécile ; Tafra, Emil ; Jacquet, Eric ; Bouzehouane, Karim ; Deranlot, Cyrile ; Hamzić, Amir ; Barthélémy, Agnes ; Fert, Albert

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
THIOX 2007 - Thin Films for Novel Oxide Devices / - Sant Feliu de Guíxols, 2007

Skup
THIOX 2007 - Thin Films for Novel Oxide Devices

Mjesto i datum
Sant Feliu de Guíxols, Španjolska, 28.03.2007. - 30.03.2007

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
diluted magnetic oxides; magnetoresistance; Shubnikov - de Haas; mobility; spintronics

Sažetak
LaAlO_3/SrTiO_3 (LAO/STO) structures showing high mobility conduction have recently raised great expectations as they might represent a major step towards the conception of all-oxide electronics devices. The low-temperature high mobility was found for LAO films deposited on STO substrates at oxygen pressures below 10^-4 mbar. Generally, this metallic behavior has been ascribed to charge transfer effects at the interface between the insulators LAO and STO. For the development of oxide-based electronic devices a full understanding of the dimensionality and origin of this conducting electronic system is crucial. We have investigated the magnetotransport properties of LAO films epitaxially grown on STO(001) substrates in a wide range of deposition pressures. We show that metallic behavior and high mobility are only obtained when the films are deposited at low pressure (<10^-5 mbar) whereas films grown at higher pressures are insulating at low T. The observation of Shubnikov-de Haas oscillations have allowed us to determine unambiguously the three-dimensional character of the high mobility gas (with mobility as high as 20 000 cm^2/Vs). In view of these results we propose that the high mobility conduction arises from the electronic properties of the STO substrates doped with oxygen vacancies, which introduce shallow-donor levels into the STO electronic structure during the growth of the LAO layer. We show that other oxides grown at low pressure on STO substrates show the same high mobility conduction. We suggest that heterostructures associating high mobility STO and magnetic oxides may offer interesting prospects for electronic and spintronics devices. .

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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