Details

Autor(en) / Beteiligte

• Herng, T S
• Qi, D-C
• Berlijn, T
• Yi, J B
• Yang, K S
• Dai, Y
• Feng, Y P
• Santoso, I
• Sánchez-Hanke, C
• Gao, X Y
• Wee, Andrew T S
• Ku, W
• Ding, J
• Rusydi, A

Titel

Room-temperature ferromagnetism of Cu-doped ZnO films probed by soft X-ray magnetic circular dichroism

Ist Teil von

• Physical review letters, 2010-11, Vol.105 (20), p.207201-207201, Article 207201

Ort / Verlag

United States

Erscheinungsjahr

2010

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• We report direct evidence of room-temperature ferromagnetic ordering in O-deficient ZnO:Cu films by using soft x-ray magnetic circular dichroism and x-ray absorption. Our measurements have revealed unambiguously two distinct features of Cu atoms associated with (i) magnetically ordered Cu ions present only in the oxygen-deficient samples and (ii) magnetically disordered regular Cu2+ ions present in all the samples. We find that a sufficient amount of both oxygen vacancies (V(O)) and Cu impurities is essential to the observed ferromagnetism, and a non-negligible portion of Cu impurities is uninvolved in the magnetic order. Based on first-principles calculations, we propose a microscopic "indirect double-exchange" model, in which alignments of localized large moments of Cu in the vicinity of the V(O) are mediated by the large-sized vacancy orbitals.