  We present the results of the first experimental study of ionization yield of
electron recoils with energies below 100 keV produced in liquid xenon by the
isotopes: 37Ar, 83mKr, 241Am, 129Xe, 131Xe. It is confirmed by a direct
measurement with 37Ar isotope (2.82 keV) that the ionization yield is growing
up with the energy decrease in the energy range below ~ 10 keV accordingly to
the NEST predictions. Decay time of scintillation at 2.82 keV is measured to be
25 +/- 3 ns at the electric field of 3.75 kV/cm.
