Magnetic, structural, and transport properties of the Heusler alloys Co2MnSi and NiMnSb -: art. no. 104430

We report on structural, magnetic, transport, and spin-polarization measurements of the Heusler alloys Co2MnSi and NiMnSb. Laue diffraction patterns confirm the single-crystal nature of Co2MnSi. Room-temperature transport measurements show a negative magnetoresistance in NiMnSb. Point-contact Andreev reflection measurements of the spin polarization yield polarization values for Co2MnSi and NiMnSb of 56% and 45%, respectively. Temperature dependence of resistivity for Co2MnSi reveals a relatively large residual resistivity ratio (rho(293 K)/rho(5 K)) typical of single-crystal Heusler alloys. In NiMnSb, resistivity and magnetization as a function of temperature show evidence of a magnetic phase transition near 90 K.