Magnetization and magneto-transport studies on Fe$_2$VAl$_{1-x}$Si$_x$

TL;DR

This study investigates how Si substitution in Fe2VAl affects its magnetoresistance, Hall effect, and magnetization, revealing a transition in electrical behavior and magnetic ordering at low temperatures.

Contribution

It provides new insights into the magnetic and transport properties of Fe2VAl1-xSix compounds, highlighting the effects of Si doping on electronic and magnetic behavior.

Findings

TCR changes from negative to positive with increasing Si

Carrier density increases with Si concentration

Magnetic ordering occurs below 60 K, with superparamagnetic clusters present

Abstract

We report on magnetoresistance, Hall and magnetization measurements of Fe2VAl1-xSix Heusler compounds for x= 0.005, 0.015, 0.02. There is a systematic change in the temperature coefficient of resistance (TCR) from negative to positive as the Si composition is increased. The Hall co-efficient shows that the carriers are electron like and the carrier density increases with Si concentration. Resistance measurements under magnetic field indicate a decreasing behavior under the application of magnetic field at low temperature region (T< 60 K), suggesting the suppression of scattering by magnetic field. Temperature and field dependent magnetization measurements did not show any significant change apart from the fact that the presence of super paramagnetic (SPM) cluster and its ordering at low temperatures. Arrott plot analysis of magnetization versus field also indicates the magnetic ordering with applied field below 60 K.