Magnetic Mn-Doped Ge Nanostructures

Figure 8

AFM and MFM images of the Mn_0.05Ge_0.95 quantum dots measured at 320 K. (a) Typical AFM image of Mn_0.05Ge_0.95 quantum dots; (b) corresponding MFM image with the tip magnetization pointing toward the sample; (c)~(f) enlarged MFM images of individual quantum dots taken from (b). From these MFM measurements, opposite contrasts were observed when applying an opposite magnetization to the tip. The results suggest that the magnetic signals come from the Mn_0.05Ge_0.95 quantum dots. The formation of Mn₅Ge₃ and Mn₁₁Ge₈ can be excluded because of their low Curie temperatures of 296~300 K.

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