Mossbauer studies of the 6.2 keV gamma-rays of sup (181) Ta in 2H-Li sub x TaS sub 2 (0 <= x <= 0.95).

High resolution Mossbauer resonance of the 6.2 keV gamma-rays of sup (181) Ta has been observed in 2H-Li sub x TaS sub 2 (0 = x = 0.95). The isomer shift (IS) results have been found to be proportional with the Li concentration and in turn to the charge transfer. The IS increases from 72.3 mm/s for x = 0 to 100 mm/s for x = 0.95. The IS results reflect the change of the electronic configuration of Ta from Ta sup (4+) (5d sup 1) toward Ta sup (3+) (5d sup 2) and an increase in ionicity as the lithium content increases from 0 to 0.95. The correlation between IS and electric quadrupole interaction suggests the observation of a metal semiconductor transition.