Emission channeling studies on transition-metal doped GaN and ZnO: Cation versus anion substitution

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:332

Article; Proceedings Paper

Pereira, L. M. C.¹  Wahl, U.²  Correia, J. G.²  Amorim, L. M.¹  Silva, D. J.^3,4  Decoster, S.¹  da Silva, M. R.⁵  Temst, K.¹  Vantomme, A.¹ 

[1] Katholieke Univ Leuven, Inst Kern & Stralingsfys, B-3001 Louvain, Belgium

[2] Univ Tecn Lisboa, Inst Super Tecn, Inst Tecnol & Nucl, P-2686953 Sacavem, Portugal

[3] Univ Porto, IFIMUP, P-4169007 Oporto, Portugal

[4] Univ Porto, IN Inst Nanosci & Nanotechnol, P-4169007 Oporto, Portugal

[5] Univ Lisbon, Ctr Fis Nucl, P-1649003 Lisbon, Portugal

关键词: Dilute magnetic semiconductors;    GaN;    ZnO;    Emission channeling;    Lattice location;    Transition metal;   

DOI  :  10.1016/j.nimb.2014.02.048

来源: Elsevier

【 摘 要 】

The magnetic and electric properties of impurities in semiconductors are strongly dependent on the lattice sites which they occupy. While the majority site can often be predicted based on chemical similarities with the host elements and is usually simple to confirm experimentally, minority sites are far more complicated to predict, detect and identify. We have carried out extensive beta(-) emission channeling studies on the lattice location of transition metal impurities in wide-gap dilute magnetic semiconductors, namely Co and Mn in GaN and ZnO, making use of radioactive Co-61 and Mn-56 implanted at the ISOLDE facility at CERN. In addition to the majority occupation of cation (Ga, Zn) sites, we located significant fractions (of the order of 20%) of the Co and Mn impurities in anion (N, O) sites, which are virtually unaffected by thermal annealing up to 900 degrees C. Here, we present the beta(-) emission channeling experiments on Co-61-implanted GaN. We discuss these results in the context of our recent reports of minority anion substitution in Mn-implanted GaN Pereira et al. (2012) [19] and Mn/Co-implanted ZnO Pereira et al. (2011) [20], particularly in terms of the advantages of the emission channeling technique in such cases of multi-site occupancy. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

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