Metal–insulator transition in compounds

Abstract: We have investigated the physical properties of compounds with pyrochlore crystal structure. The solid-solution compounds of show from metallic to insulating behaviors. These compounds with also indicate the spin-glass like behaviors at low temperature which are attributed to the geometrical frustration on pyrochlore lattice. The transition temperature decreases monotonously with decreasing x and goes to zero at . The sample with shows the metal–insulator (MI) transition at 10–30K where the sign of temperature derivative of electric resistivity changes. [Copyright &y& Elsevier]