Magnetic and electrical properties of the half-Heusler CuxNi1−xMnSb alloys

The half-Heusler type alloys CuxNi1−xMnSb compounds are fabricated by arc-melting method and subsequently are annealed at 1050 K for 24 h. The magnetic and electrical properties of the CuxNi1−xMnSb alloys with x values from 0 to 1 have been investigated. It was found that at 300 K and in a field up to 10 kOe for CuxNi1−xMnSb samples, the magnetizations almost remain unchanged for x < 0.4. When x > 0.4 the magnetization starts to decrease. For x > 0.8, the magnetizations decrease almost to zero. At 4.5 K, the range where the magnetization remains unchanged is much larger. A significant drop of the magnetization was found for further increase x, approaching zero when x is above 0.9. The experimental results revealed that the Curie temperature decreases with increasing of Cu concentration. The concentration dependence of the Curie temperature reflects the weakening in exchange energy with substitution of Cu for Ni in NiMnSb alloys. The resistivity of the materials with different values for x was measured from around 120 to 290 K. It was indicated that the resistivity rises with the increase of both x and the temperature.