Transport, Magnetic and Magnetocaloric Properties of Ho5SixGe4-x

We report on the evolution of magnetic phase transitions in the Ho5SixGe4-x compounds investigated by means of electrical-resistivity (R), magnetization (M) and specific-heat (Cp) measurements with respect to temperature and magnetic field. These materials apparently order antiferromagnetically at the Neel temperature, TN and undergo 2 order-order transitions at lower temperatures, which is reflected in the character of corresponding anomalies on the R(T) and Cp(T) curves and their evolution in an applied magnetic field. The Neel temperature decreases with increasing Si content. The applied magnetic field yields a reduction of the critical temperatures and a suppression and smearing of the reported magnetic phase transitions.