Thermal expansion and electrical resistivity of EuNi2(Si1-xGex)(2)

The thermal expansion and temperature dependence of electrical resistivity were measured for EuNi2 (Si1-xGex)(2), which shows a valence transition aga inst temperature in 0.5 less than or equal to x less than or equal to 0.82. A first-order phase transition was observed in the temperature dependence of the lattice parameters of x = 0.79 and 0.82, while the lattice parameter s vary continuously with temperature for x less than or equal to 0.70. The temperature dependence of electrical resistivity shows a peak at the valenc e transition temperature. The origin of the peak is discussed on the basis of the dynamic alloy model.