Magnetic and Electrical Properties of Impurity Doped HgCr₂Se₄

抄録

Measurements of the magnetic properties and the electrical properties (the electrical resistivity, the Hall effect and the magnetoresistance effect) were performed on hot pressed polycrystalline samples of Hg_1−xAg_xCr₂Se₄ (0≤x≤0.0155) and of Hg_1−yIn_yCr₂Se₄ (0≤y≤0.02). It was found that the Curie temperature of Hg_1−xAg_xCr₂Se₄ increased as the amount of the Ag dopant increased, whereas the Curie temperature of Hg_1−yIn_yCr₂Se₄ decreased with increasing concentration of the In dopant. The In-doped HgCr₂Se₄ showed a high resistivity, a large Hall effect, and a large negative magnetoresistance effect; the Ag-doped HgCr₂Se₄ showed a low resistivity, a small Hall effect and a small critical scattering of positive magnetoresistance. The different effects of the dopants. Ag and In, on the properties of HgCr₂Se₄ which were studied is satisfactorily explained by the change in carrier concentration produced by the dopants.