Maqola

Magnetic properties of bulk Zn1−xMnxO and Zn1−xCoxO single crystals

Matthew H. KaneDepartment of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0250K. ShaliniDepartment of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245Christopher J. SummersDepartment of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245R. VaratharajanCermet, Inc. , 1019 Collier Road Suite E, Atlanta, Georgia 30318Jeff NauseCermet, Inc. , 1019 Collier Road Suite E, Atlanta, Georgia 30318Christy R. VestalDepartment of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400Z. J. ZhangDepartment of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332-0400Ian T. FergusonDepartment of Electrical and Computer Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0250

2004en

ABI

Annotatsiya

Manganese and cobalt-doped ZnO have been produced using a modified melt-growth technique. X-ray diffraction measurements indicate that the samples are high-quality single crystals with ω−2θ full width at half maximum values of 78 arc sec for the undoped ZnO and 252 arc sec for Zn1−xMnxO (x=0.05). The lattice parameter of the Zn1−xMnxO was observed to increase with Mn concentration. Transmission measurements showed systematic variations dominated by absorption from interatomic Mn2+ and Co2+ transitions. No evidence of diluted magnetic semiconductor mean-field ferromagnetic behavior was observed in any of these nominally noncarrier-doped samples. The magnetic properties instead showed paramagnetic behavior for Zn1−xMnxO dominated by an antiferromagnetic Mn–Mn exchange interaction at low temperatures. Zn1−xCoxO showed hysteresis that was attributed to superparamagnetic Co clusters embedded in a diamagnetic ZnO matrix. It has been shown that in the bulk single-crystal form, intrinsic and noncarrier-doped Zn1−xTMxO is not ferromagnetic; thus creative processing and doping techniques are necessary to achieve practical ferromagnetism in these materials.

Hali tarjima qilinmagan

Identifikatorlar

DOI: 10.1063/1.1830084

Iqtiboslar va manbalar

3 ta iqtibos0 ta foydalanilgan manba

Koʻrsatkichlar — AkademScholar