  Geometrical frustration and spin-orbit coupling effect together play vital
role to influence properties in pyrochlore based iridium oxides. Here we have
investigated detailed structural, magnetic, thermodynamic and transport
properties of pyrochlore iridate Y$_2$Ir$_2$O$_7$. Magnetization data show
onset of magnetic irreversibility around temperature $T_{irr}$ $\sim$ 160 K,
however, no sign of long-range type ferromagnetic ordering is observed below
$T_{irr}$. Specific heat data show no visible anomaly across $T_{irr}$, and the
analysis of data indicate sizable density of states across Fermi level.
Temperature dependent x-ray diffraction measurements show no change in
structural symmetry down to low temperature. The material, on the other hand,
shows significant relaxation and aging behavior similar to glassy dynamics. The
electronic charge transport in this highly insulating system is found to follow
power law dependence with temperature. The material shows negative
magnetoresistance which is explained with quantum interference effect.

Strongly Correlated Electrons