Raman active phonons in the high-T_c superconductors: A global point of view

The two most widely studied families of high-temperature superconductors are TlBa2Can-1CunO3+2n called 1-Tl(n) and Tl2Ba2Can-1CunO4 + 2n called 2-Tl(n). We consider the structures of each family and show how some of the Raman active phonons are independent of n and some should have certain regularities depending on n. Further, we show which Raman active phonons should be essentially the same in both families of compounds. © 1990.