Electrical and magnetoelectronic properties of La_0.7Sr_0.3MnO_3/SiO_2/p-Si heterostructure for spintronics application

• Published in: Current applied physics 2011, 11(5), , pp.1153-1158
• Main Authors: S. Chattopadhyay, T.K. Nath
• Format: Article
• Language: English
• Subjects: 물리학
• ISSN: 1567-1739; 1878-1675

An experimental study of p-silicon (Si)/La_0.7Sr_0.3MnO_3 (LSMO) junction in which the LSMO and silicon are separated by a thin interfacial silicon dioxide (SiO_2) layer has been fabricated. Two type of SiO_2 layer has been discussed here ― one is native oxide and another one is thermal oxide. The thermal SiO_2 film is grown on Si by annealing it at 800 ℃ in oxygen atmosphere. The LSMO film of about 64 nm thick has been grown on SiO_2 at 800 ℃ substrate temperature in 10^-1 mbar oxygen pressure by Pulsed Laser Deposition technique. The LSMO/SiO_2/Si heterostructure exhibits MOS diode-like behavior with all type of possible current flow mechanisms (such as thermionic emission, tunneling, recombination degeneration,etc.) through the heterojunction. The high field Fowler-Nordheim [ln(J_FN/E^2) vs 1/E] plot at different temperatures confirms that the dominating transport mechanism across the heterostructure is tunneling. The junction resistance changes under magnetic field and the junction magnetoresistance is found to be ∼31% with 1T applied magnetic field at room temperature at a bias voltage of 2.2 V. The capacitor-voltage characteristics confirm the presence of trap charges. KCI Citation Count: 8