Abstract
The single-phase disordered alloys of RAlGe (R = Dy, Ho) are successfully prepared by arc-melting, and their structures and physical properties are investigated by X-ray diffraction, magnetization, specific heat, electric transport and magnetoresistance measurements. RAlGe crystallizes into an orthorhombic YAlGe-type structure with a space group of Cmcm, and three kinds of crystal positions are randomly occupied by (Al, Ge) at 4a (0, 0, 0) site, (R, Al) at 4c (0, 0.31, 0.25) site, and (Ge, R) at 4c (0, 0.61, 0.25) site, respectively. RAlGe exhibits strong relation effect among magnetic and electric as well as thermal properties, it shows that the magnetic, thermal and electric phase transitions simultaneously occur. The thermal and electric phase transitions are associated with the magnetic transition. The magnetoresistance shows the dynamic evolution from positive to negative with increasing temperature from the magnetic transition temperature Tt to Néel temperature TN. It is suggested to be due to the temperature induced magnetic phase transition from AFM-I to AFM-II, which causes the decrease of spin disordered scattering.
NSTL
Elsevier