Academic Journal
Tunnel transport through CoFe2O4 barriers investigated by conducting atomic force microscopy
| العنوان: | Tunnel transport through CoFe2O4 barriers investigated by conducting atomic force microscopy |
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| المؤلفون: | Foerster, M, Rigato, F, Bouzehouane, K, Fontcuberta, J |
| المساهمون: | Institut de Ciència de Materials de Barcelona (ICMAB), Consejo Superior de Investigaciones Científicas Madrid (CSIC), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES |
| المصدر: | ISSN: 0022-3727 ; EISSN: 1361-6463. |
| بيانات النشر: | HAL CCSD IOP Publishing |
| سنة النشر: | 2010 |
| المجموعة: | Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
| مصطلحات موضوعية: | 75.47Lx, 73.40.Gk, 81.40.Rs, 68.37Ps |
| الوصف: | International audience ; Conducting atomic force microscopy has been used to monitor the quality of spin-filtering CoFe 2 O 4 tunnel barriers by mapping current as a function of their thickness. We show that appropriate film annealing leads to a substantial improvement of their tunnelling properties. The contact force between tip and sample was identified to have a determining influence on the width of the distribution P(I) in current maps, thus precluding its reliable use to infer barrier characteristics. Therefore, assessment of tunnel transport should be done by means of the typical current which is a well defined parameter at a given contact force, rather than by the current distribution width. 2 1.Introduction Spin filters, formed by a ferromagnetic insulating layer sandwiched between two normal metal electrodes, are expected to constitute spin polarized sources of relevance in future spintronics devices [ 1 ]. Spinel ferrites such as NiFe 2 O 4 and CoFe 2 O 4 are being considered for this purpose and recently, spin filtering effects have been demonstrated using these materials [ 2-5 ]. However, as the reported spin filtering efficiency is much below expectations, questions concerning the quality/homogeneity of the spinel barriers and on their effective height arise. Characterization of tunnel devices is far from simple, as local variations of the tunnel barrier properties may produce large variations in conductance due to its extremely non-linear dependence on the barrier characteristics. Therefore the knowledge of barrier properties at submicronscale is of the highest relevance. Atomic force microscopy with a conducting tip (C-AFM) is a suitable tool to analyze electric transport across nanometric barriers. Current mapping at a given bias voltage (V) has been used to determine the dependence of the conductance of different barriers as a function of their thickness (t), eventually confirming tunnel transport across them [ 2, 3 ]. Also attempts have been made to infer barrier characteristics from current ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| Relation: | hal-00569654; https://hal.archives-ouvertes.fr/hal-00569654; https://hal.archives-ouvertes.fr/hal-00569654/document; https://hal.archives-ouvertes.fr/hal-00569654/file/PEER_stage2_10.1088%252F0022-3727%252F43%252F29%252F295001.pdf |
| DOI: | 10.1088/0022-3727/43/29/295001 |
| الاتاحة: | https://hal.archives-ouvertes.fr/hal-00569654 https://hal.archives-ouvertes.fr/hal-00569654/document https://hal.archives-ouvertes.fr/hal-00569654/file/PEER_stage2_10.1088%252F0022-3727%252F43%252F29%252F295001.pdf https://doi.org/10.1088/0022-3727/43/29/295001 |
| Rights: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.9E84C409 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1088/0022-3727/43/29/295001 |
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