Effect of Ga substitution on low temperature transport and magnetic response of Ce75Al25 metallic glass

The low temperature transport and magnetic behavior of Ce75Al25-xGax (x=0, 2, 4 and 6 at. %) metallic glasses (MGs) have been investigated. The temperature dependence of the resistance shows that the temperature coefficient of resistance (TCR) changes with Ga content. The significant change in the magnetoresistance (MR) behaviour has been observed for these alloys. The alloys with x=2, 4 and 6 show a magnetic field tuned MR transition from positive to negative values at low temperature. The magnetization (M-H) curves of the MGs at 5 K exhibit no magnetic hysteresis and show paramagnetic characteristics. However, a curious type of hysteretic behaviour for Ce75Al25-xGax alloys in non-zero magnetic field has been observed. The hysteric field range has been found to shift to higher magnetic field with increase in the value of x. It has been suggested that the formation of nano-amorphous domains in the glassy matrix and the delocalization of 4f(1) configuration of Ce atoms due to Ga substitution may result in the unusual transport behaviour of Ce-Al (Ga) MGs. These changes in the transport behaviour at low temperature have been discussed in terms of the competition between the Kondo effect and Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction. The genesis of hysteretic behaviour in M-H curve has been proposed to arise due to Anti-ferromagnetic screening interaction (AFSI) in two kinds of clusters. (C) 2018 Author(s).