Thallium barium calcium copper oxide, or TBCCO (pronounced "tibco"), is a family of high-temperature superconductors having the generalized chemical formula TlmBa2Can−1CunO2n+m+2. Tl2Ba2Ca2Cu3O10 (TBCCO-2223) was discovered in Prof. Allen M. Hermann's laboratory in the physics department of the University of Arkansas in October 1987 by the post-doctoral researcher Zhengzhi Sheng and Prof. Hermann. The bulk superconductivity in this material was confirmed by observations of magnetic flux expulsion and flux trapping signals (under zero field cooled and field cooled conditions) with a SQUID magnetometer in the superconductor laboratory of Timir Datta in the University of South Carolina. Allen Hermann announced his discovery and the critical temperature of 127 K, in Houston, Texas at the World