1 Department of Energy Conversion and Storage, Technical University of Denmark2 Electrofunctional materials, Department of Energy Conversion and Storage, Technical University of Denmark3 Hanoi University of Science and Technology
Heusler alloys known as X2YZ (full-Heusler) and XYZ (half-Hersler), where X and Y denote the transition metals and X is s-p such as Al, Ga, Sb, Sn, In, ect., have been extensively studied since they possess many important properties [1-3] like shape memory effect, magnetocaloric effect (MCE), magnetoresistance and thermoelectric effect. In this work, structure, magnetic and thermoelectric properties of the full-Hersler Ni2Mn1.52Sb0.48 alloy were investigated in terms of Boron (B) addition. We have found that the structural transition temperature i.e. the ferromagnetictoantiferromagnetic martensitic transition (TM) decreases, while the paramagneticferromagnetic austenitic transition (TC) tends to increase with increasing B concentration. Temperature dependent Xray diffraction patterns from 200 - 500 K clearly shows an evolution of the structural transformation from orthorhombic to cubic structure. It was interestingly found in the hightemperature (300 - 1000 K) thermoelectric properties, that the sample with x = 1 switches from n-type conducting behavior at temperatures below 570 K to p-type conducting one in higher temperature region. However, with higher B concentration e.g. x = 2, the sample shows n-type conducting behavior over the whole measured temperature range, again confirming the effect of boron addition.
Main Research Area:
6th International Workshop on Advanced Materials Science and Nanotechnology, 2013