Crystal Structure, Thermal Expansion And Electrical Properties Of A New Compound Al_(0.33)dyge_2

摘要

A new ternary compound Al_(0.33)DyGe_2 has been synthesized and studied from 298 K to773 K by means of X-ray powder diffraction technique. The crystal structural refinement of Al_(0.33)DyGe_2 has been performed by using the Rietveld method. The ternary compound Al_(0.33)DyGe_2 crystallizes in the orthorhombic of the defect CeNiSi2-type structure (space group Cmcm, a = 0.41018(2)nm, b= 1.62323(6)nm. c = 0.39463(1)nm, Z = 4 and D_(calc) = 8.004 g/cm~3). The average thermal expansion coefficients α_a, α_b and α_c of Al_(0.33)DyGe_2 are 1.96 ×10~(-5) K~(-1), 0.93 ×10~(-5) K~(-1) and 1.42 ×10~(-5) K~(-1), respectively. The bulk thermal expansion coefficient α_V is 4.31 × 10~(-5) K~(-1). The resistivity is observed to fall from 387 to 308 μΩ cm between room temperature and 25 K.