  We report the observation of metal-like to insulator transition (MTI) in the
3dpyrochlore oxide Tb2Ti2O7 at 603 K due to the interaction of empty 3d
orbitals of Ti4+ with O2- ions, evidenced by the transition in resistivity.
Magnetisation, specific heat capacity and differential scanning calorimetry
support the MTI, and the transition is of second order. An appreciable change
in magnetisation with temperature, without any magnetic phase transition, is a
behaviour typical in this family of compounds which is seldom observed in empty
d orbital pyrochlores. The possible mechanism that supports the MTI in Tb2Ti2O7
is discussed. Subsequently, a broad change in magnetisation from 696 K is also
seen. Thermogravimetric analysis confirms the observed MTI (603 K) and the
broad change in magnetisation (696 K)are not due to oxygen vacancy
