Department of Materials Science and Engineering, University of Maryland, College Park, Maryland, 20742, USA.
Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 50463, Republic of Korea.
Sci Rep. 2017 Sep 11;7(1):11101. doi: 10.1038/s41598-017-11078-3.
Magnetic oxide semiconductors with wide band gaps have promising spintronic applications, especially in the case of magneto-optic devices. Co-doped ZnO (ZnCoO) has been considered for these applications, but the origin of its ferromagnetism has been controversial for several decades and no substantial progress for a practical application has been made to date. In this paper, we present direct evidence of hydrogen-mediated ferromagnetism and spin polarization in the conduction band of ZnCoO. Electron density mapping reveals the formation of Co-H-Co, in agreement with theoretical predictions. Electron spin resonance measurement elucidates the ferromagnetic nature of ZnCoO by the formation of Co-H-Co. We provide evidence from magnetic circular dichroism measurements supporting the hypothesis that Co-H-Co contributes to the spin polarization of the conduction band of hydrogen-doped ZnCoO.
具有宽禁带的磁性氧化物半导体在自旋电子学应用方面具有广阔的前景，特别是在磁光器件方面。掺钴氧化锌 (ZnCoO) 已被认为可应用于这些领域，但几十年来其铁磁性的起源一直存在争议，迄今为止，在实际应用方面尚未取得实质性进展。在本文中，我们提供了在 ZnCoO 的导带中氢介导的铁磁性和自旋极化的直接证据。电子密度映射揭示了 Co-H-Co 的形成，这与理论预测一致。电子自旋共振测量通过 Co-H-Co 的形成阐明了 ZnCoO 的铁磁性。我们从磁圆二色性测量中提供了证据，支持 Co-H-Co 有助于掺氢 ZnCoO 导带自旋极化的假设。
