**2. Experimental Procedure**

The (La0.5Ce0.5)65Al10(CoxCu1−x)25 at% (x = 0, 0.2, 0.4, 0.6 and 0.8) precursor alloy was produced by arc melting in high-purity argon atmosphere, after titanium melting for the removal of residual oxygen. The alloy was re-melted at least four times to ensure chemical homogeneity. Suction casting copper method was eventually used to produce plates of 2 mm thickness.

The structural properties of the samples were checked by X-ray di ffraction (XRD, Philips PW 3830, Amsterdam, Netherlands) using monochromatic Cu-Kα radiation. The glass transition *T*g and crystallization onset *Tx* temperatures were determined by di fferential scanning calorimeter (DSC, NEZTCH 404 C, Bavaria, Germany) at a heating rate of 10 K/min. Dynamical mechanical analysis (DMA, TA Q800, USA) was used to monitor the mechanical relaxation behavior. Samples of 30 mm (length) × 2 mm (width) × 1 mm (thickness) for DMA analysis were produced on a precise water-cooled low-speed cutting machine. DMA measurements were performed on single cantilever, at a 3 K/min heating rate; the complex elastic modulus is denoted as *E* (storage modulus *E* and the loss modulus *E"*).
