Spin-Dependent Tunneling Transport into CrO2 Nanorod Devices with Nonmagnetic Contacts

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• 作者：Yipu Song ; Andrew L. Schmitt ; Song Jin
• 刊名：Nano Letters
• 出版年：2008
• 出版时间：August 2008
• 年：2008
• 卷：8
• 期：8
• 页码：2356-2361
• 全文大小：338K
• 年卷期：v.8,no.8(August 2008)
• ISSN：1530-6992

文摘

Single-crystal nanorods of half-metallic chromium dioxide (CrO₂) were synthesized and structurally characterized. Spin-dependent electrical transport was investigated in individual CrO₂ nanorod devices contacted with nonmagnetic metallic electrodes. Negative magnetoresistance (MR) was observed at low temperatures due to the spin-dependent direct tunneling through the contact barrier and the high spin polarization in the half-metallic nanorods. The magnitude of this negative magnetoresistance decreases with increasing bias voltage and temperature due to spin-independent inelastic hopping through the barrier, and a small positive magnetoresistance was found at room temperature. It is believed that the contact barrier and the surface state of the nanorods have great influence on the spin-dependent transport limiting the magnitude of MR effect in this first attempt at spin filter devices of CrO₂ nanorods with nonmagnetic contacts.