TEMPERATURE-VARIATION OF MAGNETIZATION AND ELECTRICAL-RESISTIVITY IN MNCOXSB ESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.25]

Magnetization measurements have been done from 77 K to 600 K on MnCo(x )Sb [0.1 less-than-or-equal-to x less-than-or-equal-to 0.25]. For all the concentrations other than x=0.25, the temperature variation of mag netization was found to follow the Stoner model. Anomalous behaviour o bserved in the case of MnCo0.25Sb is attributed to the exchange intera ction between Mn-Co dominating over that of the exchange interaction b etween Mn-Mn. Electrical resistivity studies carried out in the temper ature range 85-300 K show metallic behaviour for all samples excepting in the case of MnCo0.25Sb where an anomalous behaviour has been obser ved. This has been attributed to the scattering of conduction electron s due to the fluctuation of magnetic moment of Co atoms dominating ove r that due to the regular site magnetic moment of Mn atom.