Kang JS, Kim G, Wi SC, Lee SS, Choi S, Cho S, Han SW, Kim KH, Song HJ, Shin HJ, Sekiyama A, Kasai S, Suga S, Min BI. Spatial chemical inhomogeneity and local electronic structure of Mn-doped Ge ferromagnetic semiconductors.
PHYSICAL REVIEW LETTERS 2005;
94:147202. [PMID:
15904100 DOI:
10.1103/physrevlett.94.147202]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Indexed: 05/02/2023]
Abstract
We have investigated the chemical distributions and the local electronic structure of potential diluted magnetic semiconductor Ge0.94Mn0.06 single crystals using scanning photoelectron microscopy (SPEM), x-ray absorption spectroscopy (XAS), and photoemission spectroscopy (PES). The SPEM image shows the stripe-shaped microstructures, which arise from the chemical phase separation between the Mn-rich and Mn-depleted phases. The Mn 2p XAS shows that the Mn ions in the Mn-rich region are in the divalent high-spin Mn2+ states but that they do not form metallic Mn clusters. The Mn 3d PES spectrum exhibits a peak centered at approximately 4 eV below E(F) and the negligible spectral weight near E(F). This study suggests that the observed ferromagnetism in Ge1-xMnx arises from the phase-separated Mn-rich phase.
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