  We report an unusual sensitivity of electrical resistivity (rho) to an
application of a small magnetic field in an intermetallic compound, Tb5Si3,
under pressure. In this compound, there is a magnetic field-induced first-order
magnetic transition at 1.8 K. Under pressure, there is a metastable magnetic
phase after reducing the field to zero. This metastable phase is relatively of
higher rho and interestingly a small magnetic field (less than 2 kOe) in the
reverse direction results in a sharp fall of rho to restore virgin state rho.
The present finding could be relevant to spintronic applications.
