Ferromagnetism analysis of Mn-doped CuO thin films

Abstract

Mn (6.6–29.8%)-doped CuO thin film fabricated on a thermally oxidized silicon substrateby radio-frequency magnetron sputtering has been reported. The films were structurallycharacterized using x-ray diffraction with Rietveld refinement. The analysis indicates that Mnuniformly substituted at the Cu position in the CuO lattice. 5% cation vacancies were detectedat the Cu sites and are supposed to be responsible for the p-type electrical conduction ofCu1−xMnxO films. No evidence for large scale Mn aggregation was found in the composition rangeanalyzed. The origin of ferromagnetism was analyzed in the context of competition amongseveral interactions among Mn and Cu ions. A chain model was developed to simulate theferromagnetic behavior with the random Mn distribution in the samples. The consistencybetween simulation and experiment strongly indicates that the ferromagnetism mainlyarises from the super-exchange interactions of Mn–O–Cu–O–Mn coupling in the [] chain and Mn–O–Mn coupling contributes to the antiferromagnetism.