High Spin Level Structure of ¹⁹²Tl

High spin states of ¹⁹²Tl were populated by the ¹⁸¹Ta(¹⁶O, 5n)¹⁹²Tl heavy ion fusion evaporation reaction at 97 MeV beam energy. A new level scheme with 8 new levels was constructed and the level spins were tentatively assigned. The negative yrast band was extended up to 23-ħ. Systematics of signature of inversion were also discussed for the negative yrast band of odd-odd Tl istopes. Signature inversion has been found in ^196,198Tl with neutron number increasing in these four Tl isotopes, and it is explained by the competition between the strength of n-p interaction and Coriolis force.